Atlas of the Flora of New England

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Genera - S

Sabatia
Sagina
Sagittaria
Salicornia (see also Sarcocornia)
Salix
Salpiglossis
Salsola
Salvia
Salvinia
Sambucus
Samolus
Sanguinaria
Sanguisorba (see also Poteridium and Poterium)
Sanicula
Santolina
Saponaria (see also Vaccaria)
Sarcocornia
Sarracenia
Sassafras
Satureja (see also Clinopodium)
Saururus
Saxifraga (see also Micranthes)
Scabiosa
Scandix
Schenkia
Scheuchzeria
Schizachne
Schizachyrium
Schoenoplectiella
Schoenoplectus (see also Schoenoplectiella)
Schwalbea
Scilla
Scirpus (see also Bolboschoenus, Schoenoplectiella, Schoenoplectus and Trichophorum)
Scleranthus
Scleria
Sclerolepis
Scleropoa (see Catapodium)
Scorpiurus
Scorzoneroides
Scrophularia
Scutellaria
Secale
Securigera
Sedum (see also Hylotelephium, Phedimus and Rhodiola)
Selaginella
Sempervivum
Senecio (see also Jacobaea and Packera)
Senna
Sericocarpus
Sesamum
Sesbania
Sesuvium
Setaria
Shepherdia
Sherardia
Sibbaldia
Sibbaldiopsis
Sicyos
Sida
Sideritis
Sigesbeckia
Silene (see also Saponaria)
Silphium
Silybum
Sinapis
Sisymbrium
Sisyrinchium
Sium
Smilacina (See Maianthemum)
Smilax
Solanum
Solidago (see also Euthamia)
Sonchus
Sorbaria
X Sorbaronia
Sorbus (see also X Sorbaronia)
Sorghastrum
Sorghum
Sparganium
Spartina
Specularia (see Triodanis)
Spergula
Spergularia
Sphaeralcea
Sphenopholis
Spinacia
Spiraea
Spiranthes
Spirodela
Sporobolus
Stachys
Staphylea
Steironema (see Lysimachia)
Stellaria (see also Myosoton)
Stenanthium
Stipa (see Piptochaetium)
Streptopus
Strophostyles
Stuckenia
Suaeda
Subularia
Succisa (see Succisella)
Succisella
Symphoricarpos
Symphyotrichum
Symphytum
Symplocarpus
Symplocos
Syringa


SABATIA (Family: Gentianaceae)


Sabatia campanulata (Linnaeus) Torrey - Slender Marsh-pink. 2n = 34.


Pond margins.


SABATIA CAMPESTRIS Nuttall - Texas-star. 2n = 26.


Waste places, fields. From farther west and south.


Sabatia dodecandra (Linnaeus) Britton, Sterns & Poggenburg - Large Marsh-pink. 2n = 38.


Salt marshes.


Sabatia kennedyana Fernald - Plymouth Gentian. 2n = 40.


Sandy and sphagnous shores of freshwater ponds.


Sabatia stellaris Pursh - Salt-marsh Pink. 2n = 36.


Salt or brackish marshes and meadows, brackish pond shores.


Sabatia hybrid

Sabatia campanulata (Linnaeus) Torrey X S. kennedyana Fernald - .




SAGINA (Family: Caryophyllaceae)


Sagina decumbens (Elliott) Torrey & A. Gray subsp. decumbens - Trailing Pearlwort. 2n = 22, 36.


Dry, sandy soil, roadsides, sidewalk cracks.


SAGINA JAPONICA (Swartz) Ohwi - Japanese Pearlwort. 2n = 46, 64.


Dryish, waste places. From eastern Asia.


SAGINA MAXIMA A. Gray subsp. MAXIMA - Beach Pearlwort. 2n = 22, 44, 66.


Rocky shores, gravelly beaches. From farther west.


SAGINA NODOSA (Linnaeus) Fenzl subsp. NODOSA - Knotted Pearlwort. 2n = (22), (44), 56.


Moist, coastal ledges and rock crevices. From Europe. [S. NODOSA var. PUBESCENS (Mertens & W.D.J. Koch) W.D.J. Koch]


Sagina nodosa (Linnaeus) Fenzl subsp. borealis G.E. Crow - Knotted Pearlwort. 2n = 56.


Moist, coastal ledges and rock crevices.


SAGINA PROCUMBENS Linnaeus - Matted Pearlwort. 2n = 22.


Moist, gravelly or sandy roadsides, sidewalk cracks, rocky or sandy shores, sea cliffs. From Europe.



SAGITTARIA (Family: Alismataceae)


Sagittaria cuneata E. Sheldon - Wapato. 2n = 22.


Alkaline waters of muddy shores and shallow water of rivers.


Sagittaria engelmanniana J.G. Smith - . 2n = 22.


Acidic waters of shores, marshes, and bogs.


Sagittaria filiformis J.G. Smith - . 2n = 22.


Deep water of streams and in rapids. [S. subulata (Linnaeus) Buchenau var. gracillima (S. Watson) J.G. Smith]


Sagittaria graminea Michaux subsp. graminea - . 2n = 22.


Muddy or sandy shores, shallow water. [S. eatonii J.G. Smith]


Sagittaria latifolia Willdenow - . 2n = 22.


Muddy shores, ditches, bogs. [S. latifolia var. obtusa (Engelmann) Wiegand]


Sagittaria montevidensis Chamisso & Schlechtendahl subsp. spongiosa (Engelmann) Bogin - . 2n = 22.


Tidal mud flats of estuaries and salt marshes. [S. spathulata (J.G. Smith) Buchenau; Lophotocarpus spongiosus (Engelmann) J.G. Smith]


Sagittaria rigida Pursh - . 2n = 22.


Alkaline or brackish shores and shallow water.


Sagittaria subulata (Linnaeus) Buchenau - . 2n = 22.


Tidal mud.


Sagittaria teres S. Watson - . 2n = 22.


Acid, sandy pond shores.



SALICORNIA (Family: Amaranthaceae)


Salicornia bigelovii Torrey - Dwarf Saltwort. 2n = 36.


Salt marshes.


Salicornia depressa Standley - Samphire. 2n = 36.


Salt marshes. [S. europaea Linnaeus var. europaea - misapplied; S. europaea Linnaeus var. simplex (Pursh) Fernald]


Salicornia maritima S.L. Wolff & Jeffries - Slender Glasswort. 2n = 18.


Salt marshes, sea shores. [S. prostrata misapplied; S. europaea Linnaeus var. prostrata misapplied]



SALIX (Family: Salicaceae)


SALIX ALBA Linnaeus - White Willow. 2n = 76.


Low moist ground, along streams, shores, roadsides. From Eurasia. [S. ALBA var. CALVA G. Meyer; S. ALBA var. VITELLINA (Linnaeus) Stokes]


Salix amygdaloides Andersson - Peach-leaved Willow. 2n = 38.


Lake shores, low woods.


Salix arctophila Cockerell ex A. Heller - Northern Willow. 2n = 76.


Alpine meadows.


Salix argyrocarpa Andersson - Labrador Willow. 2n = 76.


Alpine or subalpine meadows.


SALIX ATROCINEREA Brotero - Rusty Willow. 2n = (74), 76.


Marshes, wooded wetlands. From Europe.


SALIX AURITA Linnaeus - Eared Willow. 2n = 38, 76.


Waste places. From Eurasia.


Salix bebbiana Sargent - Bebb Willow. 2n = 38.


Damp thickets, springy places.


Salix candida Flüggé ex Willdenow - Hoary Willow. 2n = 38.


Calcareous bogs and swamps.


SALIX CAPREA Linnaeus - Goat Willow. 2n = 38, (51), (57), (76).


Thickets, roadsides. From Europe


SALIX CINEREA Linnaeus - Gray Willow. 2n = (44), 76.


Sandy or gravelly, freshwater shores, wet thickets, moist waste places. From Eurasia.


Salix discolor Muhlenberg - Pussy Willow. 2n = 76, 95, 114.


Damp thickets, freshwater shores, swamps. [S. discolor var. overi C.R. Ball]


SALIX ELAEAGNOS Scopoli - Olive Willow. 2n = 38.


Shores, rocky banks. From Europe. [S. INCANA Schrank]


Salix eriocephala Michaux - Wand Willow. 2n = 38, (44).


Low thickets, pond shores, streambanks, swamps. [S. cordata misapplied; S. cordata Muhlenberg var. abrasa Fernald; S. rigida Muhlenberg; S. rigida var. angustata (Pursh) Fernald]


Salix herbacea Linnaeus - Dwarf Willow. 2n = 38.


Mossy rocks in alpine areas.


Salix humilis Marshall var. humilis - Prairie Willow. 2n = 38, 76.


Dry thickets, openings, dry, mixed woods. [S. humilis var. hyporhysa Fernald; S. humilis var. keweenawensis Farwell]


Salix humilis Marshall var. tristis (Aiton) Griggs - Dwarf Prairie Willow. 2n = ?


Dry barrens, open woods, swampy areas in woods. [S. humilis var. microphylla (Andersson) Fernald; S. occidentalis Walter]


Salix interior Rowlee - Sandbar Willow. 2n = 38.


Sandy or silty alluvial soil, river sandbars, streambanks, shores. [S. interior var. exterior Fernald; S. exigua Nuttall subsp. interior (Rowlee) Cronquist]


Salix lucida Muhlenberg - Shining Willow. 2n = 76.


Low grounds, freshwater shores, swamps. [S. lucida var. angustifolia Andersson; S. lucida var. intonsa Fernald]


Salix myricoides Muhlenberg - Blue-leaf Willow. 2n = ?


River thickets, gravelly shores, usually in calcareous soil. [S. glaucophylloides Fernald]


SALIX MYRSINIFOLIA Salisbury - Dark-leaved Willow. 2n = 114.


Waste places, roadsides. From Eurasia.


Salix nigra Marshall - Black Willow. 2n = 38.


Streambanks, shores, rich, low, woods.


Salix pedicellaris Pursh - Bog Willow. 2n = 38, 57, 76.


Sphagnum bogs and swamps, sphagnous shores. [S. pedicellaris var. hypoglauca Fernald; S. pedicellaris var. tenuescens Fernald]


Salix pellita (Andersson) Bebb - Satin Willow. 2n = 38, 76.


Streambanks, shores, rich, thickets.


Salix petiolaris Smith - Slender Willow. 2n = 38.


Meadows, river thickets, low, moist openings in deciduous woods. [S. gracilis Andersson; S. gracilis var. textoris Fernald; S. X subsericea (Andersson) C.K. Schneider (pro species)]


Salix planifolia Pursh - Tea-leaved Willow. 2n = 57, 76.


Alpine, subalpine and boreal meadows, streambanks, wet thickets.


SALIX PURPUREA Linnaeus - Purple Osier. 2n = 38.


Low, wet ground. From Europe.


Salix pyrifolia Andersson - Balsam Willow. 2n = 38.


Bogs, swamps, damp thickets.


Salix sericea Marshall - Silky Willow. 2n = ?


River thickets, swamps. [S. coactilis Fernald]


Salix serissima (L.H. Bailey) Fernald - Autumn Willow. 2n = 76.


Calcareous marshes, bogs and swamps.


SALIX TRIANDRA Linnaeus - Almond Willow. 2n = 38 (44), (57), (88).


Streambanks, waste places. From Eurasia.


Salix uva-ursi Pursh - Bearberry Willow. 2n = 38.


Exposed, rocky, alpine areas.


SALIX VIMINALIS Linnaeus - Osier. 2n = 38.


Streambanks, roadsides, freshwater shores. From Europe.

Salix hybrids

SALIX ALBA Linnaeus X S. petiolaris Smith - .



Salix bebbiana Sargent X S. eriocephala Michaux - .



Salix bebbiana Sargent X S. humilis Marshall var. humilis - .



Salix bebbiana Sargent X S. petiolaris Smith - .



Salix X beschelii B. Boivin - .


[S. bebbiana Sargent X S. discolor Muhlenberg]


Salix candida Flüggé ex Willdenow X S. pellita (Andersson) Bebb - .



SALIX CINEREA Linnaeus X S. eriocephala Michaux - .



Salix cordata Michaux X S. sericea Marshall - .



Salix X cryptodonta Fernald (pro species) - .


[S. bebbiana Sargent X S. candida Flüggé ex Willdenow]


Salix discolor Muhlenberg X S. eriocephala Michaux - .



Salix discolor Muhlenberg X S. humilis Marshall var. humilis - .



Salix discolor Muhlenberg X S. petiolaris Smith - .



Salix discolor Muhlenberg X S. pyrifolia Andersson - .



Salix eriocephala Michaux X S. lucida Muhlenberg - .



Salix eriocephala Michaux X S. myricoides Muhlenberg - .



Salix eriocephala Michaux X S. pedicellaris Pursh - .



Salix eriocephala Michaux X S. petiolaris Smith - .



Salix eriocephala Michaux X S. sericea Marshall - .


[S. X bebbii Gandoger - invalid name]


SALIX X FRAGILIS Linnaeus - Crack Willow.


[S. ALBA Linnaeus X S. EUXINA I.V. Belyaeva; S. X RUBENS Schrank (pro species)]


Salix X grayi C.K. Schneider - .


[S. argyrocarpa Andersson X S. planifolia Pursh]


Salix humilis Marshall var. humilis X S. petiolaris Smith - .



Salix humilis Marshall var. humilis X S. sericea Marshall - .



Salix humilis Marshall var. tristis (Aiton) Griggs X S. petiolaris Smith - .



Salix X jesupii Fernald - .


[S. ALBA Linnaeus X S. lucida Muhlenberg]


Salix lucida Muhlenberg X S. serissima (L.H. Bailey) Fernald - .



SALIX X MEYERIANA Rostkovius ex Willdenow - .


[S. PENTANDRAA Linnaeus X S. EUXINA I.V. Belyaeva; S. PENTANDRA misapplied]


Salix X peasei Fernald (pro species) - .


[S. herbacea Linnaeus X S. uva-ursi Pursh]


SALIX X PENDULINA Wenderoth - Weeping Willow.


[S. BABYLONICA Linnaeus X S. EUXINA I.V. Belyaeva; S. BABYLONICA misapplied]


Salix petiolaris Smith X S. sericea Marshall - .



Salix X rubella Bebb ex C.K. Schneider - .


[S. candida Flüggé ex Willdenow X S. eriocephala Michaux]


SALIX X SEPULCRALIS Simonkai - Weeping Willow.


[S. ALBA Linnaeus X S. BABYLONICA Linnaeus; S. BABYLONICA misapplied]


SALIX X SMITHIANA Willdenow (pro species) - .


[S. CAPREA Linnaeus X S. VIMINALIS Linnaeus; S. X SERICANS Tausch ex A. Kerner]



SALPIGLOSSIS (Family: Solanaceae)


SALPIGLOSSIS SINUATA Ruiz & Pavón - Painted-tongue. 2n = 44.


Waste places. From Chile.



SALSOLA (Family: Amaranthaceae)


SALSOLA COLLINA Pallas - Slender Russian Thistle. 2n = 18.


Waste places, roadsides, fields. From Eurasia.


SALSOLA KALI Linnaeus subsp. KALI - Common Saltwort. 2n = (30), 36, (54).


Sea beaches. From Europe.


SALSOLA KALI Linnaeus subsp. PONTICA (Pallas) Mosyakin - Prickly Russian Thistle. 2n = 18.


Sea beaches. From Eurasia, northern Africa. [S. KALI var. CAROLINIANA (Walter) Nuttall; S. CAROLINIANA Walter]


SALSOLA TRAGUS Linnaeus - Russian Thistle. 2n = (18), 36.


Sandy shores, roadsides, waste places, fields. From Eurasia. [S. IBERICA (Sennen & Pau) Botschantzev ex Czerepanov; S. KALI Linnaeus var. TENUIFOLIA Tausch; S. PESTIFER A. Nelson]



SALVIA (Family: Lamiaceae)


SALVIA AZUREA Michaux ex Vahl var. GRANDIFLORA Bentham - Blue Sage. 2n = 20.


Waste places, sidewalks. From farther west. [S. PITCHERI Torrey ex Bentham]


SALVIA FARINACEA Bentham - Mealy-cup Sage. 2n = 18, (20).


Roadsides. From south central United States.


Salvia lyrata Linnaeus - Cancerweed. 2n = 36.


Meadows.


SALVIA OFFICINALIS Linnaeus - Garden Sage. 2n = 14, (16).


Roadsides, fields, fencerows, river thickets. From southeastern Europe.


SALVIA PRATENSIS Linnaeus - Meadow Sage. 2n = (16), 18, (20), (32).


Waste places, fields, grassy hillsides, roadsides. From Europe.


SALVIA SCLAREA Linnaeus - Clary Sage. 2n = 22.


Waste places, fencerows. From Eurasia.


SALVIA SPLENDENS Sellow ex Nees - Scarlet Sage. 2n = (16), (20), (32), 44.


Waste places. From Brazil.


SALVIA TILIIFOLIA Vahl - . 2n = 22.


Waste places. From Mexico, Central and South America.


SALVIA VERTICILLATA Linnaeus - Lilac Sage. 2n = 16, (32).


Fields, meadows, waste places, roadsides. From Eurasia.


Salvia hybrid

SALVIA X SYLVESTRIS Linnaeus (pro species) - .


[S. NEMOROSA Linnaeus X S. PRATENSIS Linnaeus; S. NEMOROSA misapplied]



SALVINIA (Family: Salviniaceae)


SALVINIA MINIMA Baker - Floating Fern. 2n = 36, 54.


On still waters of ponds or slow streams. From Europe and Asia. [S. natans misapplied; S. rotundifolia misapplied]



SAMBUCUS (Family: Adoxaceae)


SAMBUCUS EBULUS Linnaeus - Danewort. 2n = (32), 36.


Roadsides. From Eurasia, northern Africa.


SAMBUCUS NIGRA Linnaeus subsp. NIGRA - European Elder. 2n = 36.


Waste ground. From Eurasia, northern Africa.


Sambucus nigra Linnaeus subsp. canadensis (Linnaeus) Bolli - Common Elder. 2n = 36.


Swamps, wet woods, damp roadsides, moist soil. [S. canadensis Linnaeus]


Sambucus racemosa Linnaeus subsp. pubens (Michaux) Hultén - Red-berried Elder. 2n = 36, (38), (42).


Rich woods, openings, often rocky. [S. pubens Michaux]



SAMOLUS (Family: Primulaceae)


Samolus parviflorus Rafinesque - Seaside Brookweed. 2n = 26.


Tidal shores, wet places. [S. floribundus Kunth]



SANGUINARIA (Family: Papaveraceae)


Sanguinaria canadensis Linnaeus - Bloodroot. 2n = 18.


Rich woods.



SANGUISORBA (Family: Rosaceae)


Sanguisorba canadensis Linnaeus - American Burnet. 2n = 28, 56.


Meadows, swamps, low ground, sphagnous soils.


SANGUISORBA OFFICINALIS Linnaeus - Great Burnet. 2n = (14), 28, (42), 56.


Roadsides, fields, thickets. From Eurasia, northwestern North America.



SANICULA (Family: Apiaceae)


Sanicula canadensis Linnaeus var. canadensis - . 2n = 16.


Rich woodlands.


Sanicula canadensis Linnaeus var. grandis - . 2n = ?


Rich woodlands.


Sanicula marilandica Linnaeus - Black Snakeroot. 2n = 16.


Open woodlands, thickets, often in dry, rich, rocky soil.


Sanicula odorata (Rafinesque) Pryer & Phillippe - . 2n = 16.


Rich woodlands. [S. gregaria E.P. Bicknell]


Sanicula trifoliata E.P. Bicknell - . 2n = ?


Rich woodlands.



SANTOLINA (Family: Asteraceae)


SANTOLINA CHAMAECYPARISSUS Linnaeus - Lavender-cotton. 2n = 18, (36), (45).


Dry, sandy banks, roadsides, thin, pine woods. From Europe.



SAPONARIA (Family: Caryophyllaceae)


SAPONARIA OCYMOIDES Linnaeus - Rock Soapwort. 2n = 28.


Waste places. From Europe.


SAPONARIA OFFICINALIS Linnaeus - Bouncing-bet. 2n = 28.


Roadsides, waste places, fields. From Eurasia.


SAPONARIA PUMILIO Boissier - Pygmy Pink. 2n = ?


Ledges. From Europe. [SILENE PUMILIO (Linnaeus) Wulfen]



SARCOCORNIA (Family: Amaranthaceae)


Sarcocornia ambigua (Michaux) M.A. Alonso & M.B. Crespo - Woody Glasswort. 2n = 18.


Sea beaches, tidal flats, salt marshes. [S. pacifica misapplied; Salicornia virginica misapplied]



SARRACENIA (Family: Sarraceniaceae)


SARRACENIA FLAVA Linnaeus - Trumpets. 2n = 26.


Floating Sphagnum mats. From farther south.


Sarracenia purpurea Linnaeus subsp. purpurea - Common Pitcher-plant. 2n = 26.


Peaty soil of bogs, swamps and pond margins.



SASSAFRAS (Family: Lauraceae)


Sassafras albidum (Nuttall) Nees - Sassafras. 2n = 48.


Woods, thickets, woodland borders. [S. albidum var. molle (Rafinesque) Fernald]



SATUREJA (Family: Lamiaceae)


SATUREJA HORTENSIS Linnaeus - Summer Savory. 2n = (45), 48.


Waste places, fields, railroads, roadsides, gravelly banks. From Eurasia.



SAURURUS (Family: Saururaceae)


Saururus cernuus Hooker & Arnott - Lizard's-tail. 2n = 22.


Stream borders, shallow water, swamps, marshes.



SAXIFRAGA (Family: Saxifragaceae)


Saxifraga aizoides Linnaeus - Yellow Mountain Saxifrage. 2n = 26.


Calcareous cliffs.


Saxifraga cernua Linnaeus - Nodding Saxifrage. 2n = 24, 36, 48, 50, 52, 56, 60, 62, 64, 70, 72.


Wet ledges at high altitude.


Saxifraga oppositifolia Linnaeus subsp. oppositifolia - Purple Mountain Saxifrage. 2n = 26, (39), (48), (52).


Calcareous cliffs.


Saxifraga paniculata Miller - White Mountain Saxifrage. 2n = 28.


Rocky ledges, often calcareous. [S. aizoon Jacquin var. neogaea Butters]


Saxifraga rivularis Linnaeus subsp. rivularis - Alpine Brook Saxifrage. 2n = (26), (48), 52, (56).


Wet, mossy, alpine areas.



SCABIOSA (Family: Caprifoliaceae)


SCABIOSA OCHROLEUCA Linnaeus - Cream Scabious. 2n = 16, (24).


Waste places, gravel pits. From Eurasia.



SCANDIX (Family: Apiaceae)


SCANDIX PECTEN-VENERIS Linnaeus - Shepherd’s-needle. 2n = (16), 26, (28), (34).


Waste places. From Eurasia, northern Africa.



SCHENKIA (Family: Gentianaceae)


SCHENKIA SPICATA (Linnaeus) G. Mansion - . 2n = 22.


Salt marshes. From Mediterranean region, western Russia, southwestern Asia. [CENTAURIUM SPICATUM (Linnaeus) Fritsch]



SCHEUCHZERIA (Family: Scheuchzeriaceae)


Scheuchzeria palustris Linnaeus - . 2n = 22.


Sphagnum bogs. [S. palustris var. americana Fernald]



SCHIZACHNE (Family: Poaceae)


Schizachne purpurascens (Torrey) Swallen subsp. purpurascens - False Melic. 2n = 20.


Rich woods.



SCHIZACHYRIUM (Family: Poaceae)


Schizachyrium scoparium (Michaux) Nash var. scoparium - Little Bluestem. 2n = 40.


Dry soil, old fields, open woods. [Andropogon scoparius Michaux var. scoparius; A. scoparius var. frequens F.T. Hubbard; A. scoparius var. septentrionalis Fernald & Griscom]


Schizachyrium scoparium (Michaux) Nash var. littorale (Nash) Gould - . 2n = ?


Upper borders of sea beaches, dunes. [Andropogon littoralis Nash; A. scoparius Michaux var. ducis Fernald & Griscom; A. scoparius var. littoralis (Nash) Hitchcock; S. littorale (Nash) E.P. Bicknell]



SCHOENOPLECTIELLA (Family: Cyperaceae)


Schoenoplectiella hallii (A. Gray) Lye - . 2n = 22.


Sandy or sphagnous pond shores. [Schoenoplectus hallii (A. Gray) S.G. Smith; Scirpus hallii A. Gray; S. supinus Linnaeus var. hallii (A. Gray) A. Gray]


SCHOENOPLECTIELLA MUCRONATA (Linnaeus) J. Jung & H.K. Choi - . 2n = (38), (40). (42), 44.


Pond shores. From Eurasia, Africa, Australia. [SCHOENOPLECTUS MUCRONATUS (Linnaeus) Palla; SCIRPUS MUCRONATUS Linnaeus]


Schoenoplectiella purshianus (Fernald) Lye var. purshianus - . 2n = 36, 38.


Freshwater shores, usually in sandy soil. [Schoenoplectus purshianus (Fernald) M.T. Strong var. purshianus; Scirpus purshianus Fernald]


Schoenoplectiella purshianus (Fernald) Lye var. williamsii (Fernald) Hayasaka - . 2n = 38.


Sandy lake shores. [Schoenoplectus purshianus (Fernald) M.T. Strong var. williamsii S.G. Smith; Scirpus debilis Lamarck var. williamsii Fernald; S. purshianus Fernald forma williamsii (Fernald) Fernald]


Schoenoplectiella smithii (A. Gray) Hayasaka var. smithii - . 2n = (18), 40


Sandy or muddy shores. [Schoenoplectus smithii (A. Gray) Soják var. smithii; Scirpus smithii A. Gray]


Schoenoplectiella smithii (A. Gray) Hayasaka var. leviseta (Fassett) Hayasaka - . 2n = 40.

Coastal, freshwater tidal flats. [Schoenoplectus smithii (A. Gray) Soják var. levisetus (Fassett) S.G. Smith; Scirpus smithii A. Gray forma levisetus (Fassett) Fernald] [This taxon is not mapped since it is inadequately separated from the typical variety in collections.]


Schoenoplectiella smithii (A. Gray) Hayasaka var. setosa (Fernald) Hayasaka - . 2n = 40.

Freshwater, sandy or muddy shores. [Schoenoplectus smithii (A. Gray) Soják var. setosus (Fernald) S.G. Smith; Scirpus smithii A. Gray forma setosus Fernald] [This taxon is not mapped since it is inadequately separated from the typical variety in collections.]



SCHOENOPLECTUS (Family: Cyperaceae)


Schoenoplectus acutus (Muhlenberg ex Bigelow) Á. Löve & D. Löve var. acutus Hard-stem Bulrush - . 2n = 36, 38, 40, 42.


Shores and marshes. [Scirpus acutus Muhlenberg ex Bigelow]


Schoenoplectus americanus (Persoon) Volkart ex Schinz & R. Keller Sword-grass - . 2n = (38), (76), 78.


Shores and marshes. [Scirpus americanus Persoon; S. olneyi A. Gray]


Schoenoplectus heterochaetus (Chase) Soják Slender Bulrush - . 2n = 36, 38.


Calcareous or basic shores and marshes. [Scirpus heterochaetus Chase]


Schoenoplectus pungens (Vahl) Palla var. pungens Chair-maker's Bulrush - . 2n = 74, 78.


Shores and marshes. [Scirpus pungens Vahl]


Schoenoplectus subterminalis (Torrey) Soják Water Bulrush - . 2n = 74.


Shores and Sphagnum bogs. [Scirpus subterminalis Torrey]


Schoenoplectus tabernaemontani (C.C. Gmelin) Palla Great Bulrush - . 2n = (38), (40), 42.


In shallow water of shores and marshes. [Scirpus validus Vahl; S. validus Vahl var. creber Fernald]


Schoenoplectus torreyi (Olney) Palla - . 2n = 42, 70.


Shores and marshes. [Scirpus torreyi Olney]


Schoenoplectus hybrids

Schoenoplectus acutus (Muhlenberg ex Bigelow) Á. Löve & D. Löve X S. tabernaemontani (C.C. Gmelin) Palla



Schoenoplectus X contortus (Eames) S.G. Smith - .


[S. americanus (Persoon) Volkart ex Schinz & R. Keller X S. pungens (Vahl) Palla]


Schoenoplectus X oblongus (T. Koyama) Soják - .


[S. acutus (Muhlenberg ex Bigelow) Á. Löve & D. Löve X S. heterochaetus (Chase) Soják]


Schoenoplectus X steinmetzii (Fernald) S.G. Smith - .


[S. heterochaetus (Chase) Soják X S. tabernaemontani (C.C. Gmelin) Palla]



SCHWALBEA (Family: Orobanchaceae)


Schwalbea americana Linnaeus - Chaffseed. 2n = 32, 36.


Pine-oak woods, clearings, sandy fields.



SCILLA (Family: Asparagaceae)


SCILLA SIBERICA Andrews - . 2n = 12, 18, (24), (30).


Roadsides, pastures. From Eurasia.



SCIRPUS (Family: Cyperaceae)


Scirpus ancistrochaetus Schuyler - . 2n = 54.


Wet depressions, bogs.


Scirpus atrocinctus Fernald - . 2n = 68.


Meadows and swamps.


Scirpus atrovirens Willdenow - . 2n = (50), 56, (62).


Marshes, meadows, bogs.


Scirpus cyperinus (Linnaeus) Kunth Common Wool-grass - . 2n = (60), (64), 66, (68), (70).


Meadows, swamps and ditches.  [S. cyperinus var. pelius Fernald; S. rubricosus Fernald]


Scirpus expansus Fernald Woodland Bulrush - . 2n = 64.


Marshes, meadows and springy spots.


Scirpus georgianus R.M. Harper - . 2n = 48, 50, 52, 54.


Marshes, meadows and ditches.  [S. atrovirens Willdenow var. georgianus (R.M. Harper) Fernald]


Scirpus hattorianus Makino - . 2n = 56.


Marshes, meadows and ditches.  [S. atrovirens misapplied; S. georgianus misapplied]


Scirpus longii Fernald - . 2n = 66, 68.


Freshwater marshes, meadows.


Scirpus microcarpus J. Presl & C. Presl - . 2n = 62, 64, 66.


Damp, open soil, marshes, meadows, often along rivers. [S. rubrotinctus Fernald]


SCIRPUS PALLIDUS (Britton) Fernald - . 2n = 56.


Marshes, ditches and other low ground. From farther west.


Scirpus pedicellatus Fernald - . 2n = 68, (136).


Alluvial thickets, shores.  [S. pedicellatus var. pullus Fernald]


Scirpus pendulus Muhlenberg - . 2n = 40.


Meadows, marshes, ditches, often in calcareous soil.  [S. lineatus misapplied]


Scirpus polyphyllus Vahl - . 2n = 58.


Swamps and woods along streams.

Scirpus hybrids

Scirpus ancistrochaetus Schuyler X S. hattorianus Makino



Scirpus atrocinctus Fernald X S. hattorianus Makino



Scirpus atrovirens Willdenow X S. polyphyllus Vahl



Scirpus expansus Fernald X S. microcarpus J. Presl & C. Presl



Scirpus X peckii Britton (pro species) - .


[This name is said to have been applied to various hybrids of S. hattorianus Makino and S. atrocinctus Fernald or S. pedicellatus Fernald.]



SCLERANTHUS (Family: Caryophyllaceae)


SCLERANTHUS ANNUUS Linnaeus subsp. ANNUUS - Annual Knawel. 2n = (22), 44.


Roadsides, waste places, dry, sandy soil. From Eurasia, northern Africa.


SCLERANTHUS PERENNIS Linnaeus subsp. PERENNIS - Perennial Knawel. 2n = 22, 44.


Roadsides, dry, sandy soil. From Eurasia.



SCLERIA (Family: Cyperaceae)


Scleria pauciflora Muhlenberg ex Willdenow var. pauciflora - . 2n = ?


Meadows and moist woods.


Scleria pauciflora Muhlenberg ex Willdenow var. caroliniana Alph. Wood - . 2n = ?


Moist grasslands.


Scleria reticularis Michaux - . 2n = ?


Sandy pond shores.


Scleria triglomerata Michaux - . 2n = ?


Meadows and dry, open woods. [S. nitida Willdenow ex Kunth]


Scleria verticillata Muhlenberg ex Willdenow - . 2n = ?


Calcareous bogs and shores.



SCLEROLEPIS (Family: Asteraceae)


Sclerolepis uniflora (Walter) Britton, Sterns, & Poggenberg - Pink Bogbutton. 2n = 30, ca. 60.


Sandy or sphagnous shores or shallow water of ponds and lakes.



SCORPIURUS (Family: Fabaceae)


SCORPIURUS MURICATUS Linnaeus - Caterpillar-plant. 2n = 28.


Wool waste. From the Mediterranean.



SCORZONEROIDES (Family: Asteraceae)


SCORZONEROIDES AUTUMNALIS (Linnaeus) Moench - Fall Dandelion. 2n = 12, (14), (16), (32).


Fields, meadows, roadsides. From Eurasia. [LEONTODON AUTUMNALIS Linnaeus var. AUTUMNALIS; L. AUTUMNALIS var. PRATENSIS Koch]



SCROPHULARIA (Family: Scrophulariaceae)


Scrophularia lanceolata Pursh - . 2n = 96.


Fields, thickets, woodland margins, open woods, roadsides.


Scrophularia marilandica Linnaeus - Carpenter’s-square. 2n = ca. 86.


Woods, thickets, roadsides, streambanks.


SCROPHULARIA NODOSA Linnaeus - European Figwort. 2n = 36.


Thickets, roadsides, waste places. From Eurasia.



SCUTELLARIA (Family: Lamiaceae)


Scutellaria galericulata Linnaeus - Marsh Skullcap. 2n = (28), 30, (31), 32.


Swamps, shores, meadows, marshes. [S. epilobiifolia A. Hamilton]


Scutellaria integrifolia Linnaeus - . 2n = 32.


Fields, meadows.


Scutellaria lateriflora Linnaeus var. lateriflora - Mad-dog Skullcap. 2n = 80, 88.


Wet woodlands, shores, meadows, alluvial thickets, marshes.


Scutellaria parvula Michaux var. parvula - . 2n = 20.


Rocky outcrops of shores and fields.


Scutellaria parvula Michaux var. missouriensis (Torrey) Goodman & C.A. Lawson - . 2n = 20.


Rocky outcrops of shores, fields, ridges, hills, and open woodlands. [S. parvula var. leonardi (Epling) Fernald]

Scutellaria hybrid

Scutellaria X churchilliana Fernald (pro species) - .


[S. galericulata Linnaeus X S. lateriflora Linnaeus]



SECALE (Family: Poaceae)


SECALE CEREALE Linnaeus - Rye. 2n = (7), 14, (16), (18), (21), (27), (28), (29).


Waste places, roadsides. From Eurasia.



SECURIGERA (Family: Fabaceae)


SECURIGERA VARIA (Linnaeus) Lassen - Crown-vetch. 2n = (16), 24.


Roadsides, fields, waste places. From Eurasia. [CORONILLA VARIA Linnaeus]



SEDUM (Family: Crassulaceae)


SEDUM ACRE Linnaeus - Mossy Stonecrop. 2n = (16), (24), 40, (48), (56), 60, 80, (100), (120).


Rock outcrops, rock walls, dry, open places. From Europe and Greenland.


SEDUM ALBUM Linnaeus - White Stonecrop. 2n = (18), 34, (36), (51), (64), 68, (85), (102), (136).


Rocky soil. From Europe.


SEDUM HISPANICUM Linnaeus - Spanish Stonecrop. 2n = 14, (20), (28), (30), (40), (42).


Roadsides, rocky fields. From Eurasia.


SEDUM OCHROLEUCUM Chaix - . 2n = 34, 68, (51), (85), (102).


Roadsides, rocky fields, waste places. From Europe. [S. ANOPETALUM de Candolle]


SEDUM RUPESTRE Linnaeus - Jenny's Stonecrop. 2n = (56), (88), (102), (108), 112, (120), (122), (140), (153), (168).


Roadsides, waste places. From Europe. [S. REFLEXUM Linnaeus]


SEDUM SARMENTOSUM Bunge - Stringy Stonecrop. 2n = 58, 72.


Roadsides, waste places. From China.


SEDUM SEXANGULARE Linnaeus - Tasteless Stonecrop. 2n = (72), 74, (108), (111), (148), (185).


Roadsides, waste places. From Europe.


SEDUM TERNATUM Michaux - Wild Stonecrop. 2n = 16, 24, 32, 48.


Damp roadsides. From farther south or west.



SELAGINELLA (Family: Selaginellaceae)


Selaginella apoda (Linnaeus) C. Morren - Meadow Spikemoss. 2n = 18.


Meadows, stream banks, wet rocks, often in circumneutral soils.


Selaginella eclipes W.R. Buck - . 2n = ?


Wet hillsides, stream banks.


Selaginella rupestris (Linnaeus) Spring - Rock Spikemoss. 2n = 18.


Exposed, dry rocks or packed sands.


Selaginella selaginoides (Linnaeus) Schrank & Martius - Northern Spikemoss. 2n = 18.


Damp shores and banks, bogs, springs, often calcareous.



SEMPERVIVUM (Family: Crassulaceae)


SEMPERVIVUM TECTORUM Linnaeus - Hens-and-chickens. 2n = 36, 40, 72.


Rocky outcrops, ledges, stone walls, other rocky sites. From Europe.



SENECIO (Family: Asteraceae)


SENECIO EREMOPHILUS Richardson var. MACDOUGALII (A. Heller) Cronquist - . 2n = 40.


From farther west. [S. MACDOUGALII A. Heller]


Senecio suaveolens (Linnaeus) Elliott - . 2n = (36), 40.


Stream banks, thickets, rich woods. [Cacalia suaveolens Linnaeus; Hasteola suaveolens (Linnaeus) Pojarkova]


SENECIO SYLVATICUS Linnaeus - Heath Groundsel. 2n = 40.


Cliff crevices, sandy beaches, gravelly seashores, waste places, roadsides. From Europe.


SENECIO VISCOSUS Linnaeus - . 2n = (20), (24), 40.


Waste places. From Eurasia.


SENECIO VULGARIS Linnaeus - Common Groundsel. 2n = (20), (27), (38), 40.


Roadsides, waste places. From Eurasia, northern Africa.



SENNA (Family: Fabaceae)


Senna hebecarpa (Fernald) H.S. Irwin & Barneby - Wild Senna. 2n = ?


Streambanks, thickets, roadsides, fields. [Cassia hebecarpa Fernald]


SENNA OBTUSIFOLIA (Linnaeus) H.S. Irwin & Barneby - Java-bean. 2n = (24), 26, 28, (52), (56).


Waste places. From farther south.



SERICOCARPUS (Family: Asteraceae)


Sericocarpus asteroides (Linnaeus) Britton, Sterns, & Poggenberg - Toothed White-top Aster. 2n = 18.


Dry woods, clearings, and fields, roadsides. [Aster paternus Cronquist]


Sericocarpus linifolius (Linnaeus) Britton, Sterns, & Poggenberg - 2n = 18, (54).


Dry woods, clearings, and fields, roadsides. [Aster solidagineus Michaux]



SESAMUM (Family: Pedaliaceae)


SESAMUM INDICUM Linnaeus - Sesame. 2n = (18), 26, (52).


Waste places. Long cultivated, possibly from Africa or India. [S. ORIENTALE Linnaeus]



SESBANIA(Family: Fabaceae)


SESBANIA HERBACEA (Miller) McVaugh - . 2n = 12.


Waste places. From farther south. [S. EXALTATA (Rafinesque) Rydberg]



SESUVIUM (Family: Aizoaceae)


Sesuvium maritimum (Walter) Britton, Sterns, & Poggenberg - . 2n = ?


Pond shore behind coastal dune.



SETARIA (Family: Poaceae)


SETARIA FABERI R.A.W. Herrmann - . 2n = 36.


Roadsides, railroads, waste places, fields. From eastern Asia.


SETARIA ITALICA (Linnaeus) P. Beauvois - Foxtail Millet. 2n = 18, (36).


Cultivated land, waste places, roadsides. From the Old World.


Setaria parviflora (Poiret) Kerguélen var. parviflora - . 2n = 36, 72.


Salt marsh borders, hillsides, waste places. [S. geniculata misapplied]


SETARIA PUMILA (Poiret) Roemer & Schultes - Yellow Foxtail. 2n = (18), 36, (54), (72).


Dry sandy soil, roadsides, waste places. From Europe. [S. GLAUCA misapplied; S. LUTESCENS (Stuntz) F.T. Hubbard]


SETARIA VERTICILLATA (Linnaeus) P. Beauvois - Bur Foxtail. 2n = 18, 36, 54, (72), (108).


Waste places. From Eurasia.


SETARIA VIRIDIS (Linnaeus) P. Beauvois var. VIRIDIS - Green Foxtail. 2n = 18, (36).


Fields, roadsides, railroads, waste places. From Europe. [S. VIRIDIS var. BREVISETA (Döll) Hitchcock; S. VIRIDIS var. WEINMANNII (Roemer & Schultes) Heynhold]



SHEPHERDIA (Family: Elaeagnaceae)


Shepherdia canadensis (Linnaeus) Nuttall - Soapberry. 2n = 22.


Calcareous ledges and rocky outcrops along shores of rivers and lakes.



SHERARDIA (Family: Rubiaceae)


SHERARDIA ARVENSIS Linnaeus - Field-Madder. 2n = 22.


Fields, waste places. From Eurasia. [GALIUM SHERARDIA E.H.L. Krause]



SIBBALDIA (Family: Rosaceae)


Sibbaldia procumbens Linnaeus - 2n = 14.


Headwalls of alpine ravines.



SIBBALDIOPSIS (Family: Rosaceae)


Sibbaldiopsis tridentata (Aiton) Rydberg - Three-toothed Cinquefoil. 2n = 28.


Dry, open, rocky, gravelly or sandy, sterile soil, clefts in ledges, often at high altitudes. [Potentilla tridentata Aiton]



SICYOS (Family: Cucurbitaceae)


Sicyos angulatus Linnaeus - Bur-cucumber. 2n = 24.


Waste places. From eastern Mediterranean region, southwestern Asia.



SIDA (Family: Malvaceae)


SIDA HERMAPHRODITA (Linnaeus) Rusby - Virginia Mallow. 2n = ?


Waste places, fields. From farther south.


SIDA SPINOSA Linnaeus - Prickly Mallow. 2n = 14, 28.


Waste places, wool waste, fields. From tropical Americas, tropical Africa, tropical Asia.



SIDERITIS (Family: Lamiaceae)


SIDERITIS MONTANA Linnaeus - . 2n = 16, (18), (28), 32.


Waste places, dry, open ground. From Eurasia, northwestern Africa.



SIGESBECKIA (Family: Asteraceae)


SIGESBECKIA JORULLENSIS Kunth - 2n = 30, (ca. 32).


Waste places. From Mexico, Central America, South America.



SILENE (Family: Caryophyllaceae)


Silene acaulis (Linnaeus) Jacquin - Moss Campion. 2n = (12), 24.


Alpine areas. [S. acaulis var. exscapa (Allioni) F.N. Williams]


Silene antirrhina Linnaeus - Sleepy Catchfly. 2n = 24.


Dry, sandy or rocky soil, railroads, fields, waste places.


SILENE ARMERIA Linnaeus - Garden Catchfly. 2n = 24.


Waste places, roadsides. From Eurasia. [ATOCION ARMERIA (Linnaeus) Rafinesque]


Silene caroliniana Walter subsp. pensylvanica (Michaux) R.T. Clausen - Wild Pink. 2n = 48.


Dry, often rocky, mainly deciduous woods and clearings.


SILENE CHALCEDONICA (Linnaeus) E.H.L. Krause - Maltese-cross. 2n = (18), 24, (48).


Roadsides, near habitations, waste places, open woods. From Eurasia. [LYCHNIS CHALCEDONICA Linnaeus]


SILENE CONICA Linnaeus subsp. CONICA - Sand Catchfly. 2n = (18), 20, (24).


Sandy fields and roadsides. From Eurasia.


SILENE CORONARIA (Linnaeus) Clairville - Mullein Pink. 2n = 24.


Waste places, roadsides, fields. From Europe. [LYCHNIS CORONARIA (Linnaeus) Desrousseaux]


SILENE CSEREII Baumgarten - Balkan Catchfly. 2n = 24.


Waste places, roadsides, railroads. From Europe.


SILENE DICHOTOMA Ehrhart subsp. DICHOTOMA - Forked Catchfly. 2n = 24, (48).


Fields, roadsides, waste places. From Europe.


SILENE DIOICA (Linnaeus) Clairville - Red Campion. 2n = 24.


Fields, roadsides, waste places. From Europe. [LYCHNIS DIOICA Linnaeus]


SILENE FLOS-CUCULI (Linnaeus) Clairville subsp. FLOS-CUCULI - Ragged Robin. 2n = 24.


Wet fields, meadows, roadside ditches. From Europe. [LYCHNIS FLOS-CUCULI Linnaeus]


SILENE GALLICA Linnaeus - French Catchfly. 2n = 24.


Waste places, roadsides. From Europe.


SILENE LATIFOLIA Poiret - White Campion. 2n = 24, (48).


Waste places, roadsides, field borders. From Eurasia. [S. LATIFOLIA subsp. ALBA (Miller) Greuter & Burdet; S. PRATENSIS (Rafinesque) Grenier & Godron; LYCHNIS ALBA Miller]


SILENE NIVEA (Nuttall) Muhlenberg ex Otth - Snowy Campion. 2n = 48.


Rich, shaded riverbanks. From farther west and south.


SILENE NOCTIFLORA Linnaeus - Night-flowering Catchfly. 2n = 24.


Arable land, waste places. From Europe.


SILENE NUTANS Linnaeus - Nottingham Catchfly. 2n = 24, (28).


Roadsides. From Eurasia.


SILENE PENDULA Linnaeus - Nodding Catchfly. 2n = 24.


Roadsides, fields. From Europe.


Silene stellata (Linnaeus) W.T. Aiton - Starry Campion. 2n = (34), 48.


Dry, open woods.


SILENE VISCARIA (Linnaeus) Jessen subsp. VISCARIA - German Catchfly. 2n = 24.


Roadsides, waste places, thickets, fields. From Europe. [LYCHNIS VISCARIA Linnaeus; VISCARIA VULGARIS Bernhardi]


SILENE VULGARIS (Moench) Garcke subsp. VULGARIS - Bladder Campion. 2n = (12), 24, (48).


Waste places, roadsides, field borders. From Europe. [S. CUCUBALUS Wibel; S. LATIFOLIA (Miller) Britten & Rendle -- invalid name]

Silene hybrid

SILENE X HAMPEANA Meusel & K. Werner - .


[S. DIOICA (Linnaeus) Clairville X S. LATIFOLIA Poiret]



SILPHIUM (Family: Asteraceae)


SILPHIUM PERFOLIATUM Linnaeus var. PERFOLIATUM - Cup-plant. 2n = 14, (16).


Moist thickets, low, open woods, moist roadsides, waste places. From farther west and south.



SILYBUM (Family: Asteraceae)


SILYBUM MARIANUM (Linnaeus) Gaertner - Milk Thistle. 2n = 34.


Waste places. From Eurasia, northern Africa.



SINAPIS (Family: Brassicaceae)


SINAPIS ALBA Linnaeus - White Mustard. 2n = 24.


Roadsides, waste places, railroads. From Eurasia. [BRASSICA ALBA (Linnaeus) Rabenhorst; B. HIRTA Moench]


SINAPIS ARVENSIS Linnaeus - Charlock. 2n = (16), 18.


Waste places, fields, roadsides. From Eurasia. [BRASSICA KABER (de Candolle) L.C. Wheeler; B. KABER var. PINNATIFIDA (Stokes) L.C. Wheeler; B. KABER var. SCHKUHRIANA (Reichenbach) L.C. Wheeler]



SISYMBRIUM (Family: Brassicaceae)


SISYMBRIUM ALTISSIMUM Linnaeus - Tumble-mustard. 2n = 14.


Waste places, fields, roadsides. From Eurasia, northwestern Africa.


SISYMBRIUM IRIO Linnaeus - London Rocket. 2n = 14, (16), (21), (28), (42), (56).


Roadsides, railroads, waste places. From Eurasia, northern Africa.


SISYMBRIUM LOESELII Linnaeus - False London Rocket. 2n = 14.


Waste places, fields, roadsides. From Eurasia.


SISYMBRIUM OFFICINALE (Linnaeus) Scopoli - Hedge-mustard. 2n = 14.


Waste places, roadsides, fields. From Eurasia, northern Africa. [S. OFFICINALE var. LEIOCARPUM de Candolle]


SISYMBRIUM ORIENTALE Linnaeus - Indian Hedge-mustard. 2n = 14.


Waste places, roadsides. From Eurasia, northern Africa.



SISYRINCHIUM (Family: Iridaceae)


Sisyrinchium albidum Rafinesque - . 2n = 32, (64).


Dry, sandy, open soil and thin woodlands.


Sisyrinchium angustifolium Miller - Stout Blue-eyed Grass. 2n = 96.


Meadows, fields, low woods, thickets, damp shores. [S. bermudiana misapplied; S. graminoides E.P. Bicknell]


Sisyrinchium atlanticum E.P. Bicknell - Eastern Blue-eyed Grass. 2n = 16, 32, 96.


Meadows, marshes, low woods.


Sisyrinchium fuscatum E.P. Bicknell - . 2n = 32.


Grasslands, mostly sandy soils. [S. arenicola E.P. Bicknell]


Sisyrinchium montanum Greene var. crebrum Fernald - Common Blue-eyed Grass. 2n = 32, 86, 96.


Fields, meadows, open woods. [S. angustifolium misapplied]


Sisyrinchium mucronatum Michaux - Slender Blue-eyed Grass. 2n = (30), 32.


Meadows, fields, sandy places, open woods.



SIUM (Family: Apiaceae)


Sium suave Walter - Water-parsnip. 2n = 12, (22).


Swamps, shores, meadows, wet thickets, brooks, shallow water of streams. [S. carsonii Durand ex A. Gray]



SMILAX (Family: Smilacaceae)


Smilax glauca Walter - Sawbrier. 2n = 28, 32.


Sandy thickets, open woods. [S. glauca Walter var. leurophylla S.F. Blake]


Smilax herbacea Linnaeus - Carrion-flower. 2n = 26.


Rich thickets, low woodlands.


Smilax rotundifolia Linnaeus - Common Greenbrier. 2n = ?


Woodlands, thickets.


Smilax tamnoides Linnaeus - China-root. 2n = ?


Low woodlands, thickets. [S. tamnoides var. hispida (Muhlenberg ex Torrey) Fernald; S. hispida Muhlenberg ex Torrey]



SOLANUM (Family: Solanaceae)


SOLANUM CAPSICOIDES Allioni - Cockroach-berry. 2n = 24.


Waste places. From South America. [S. SPHAEROCARPUM Moricand]


SOLANUM CAROLINENSE Linnaeus - Horse-nettle. 2n = 24, (48).


Dry fields, openings, roadsides, railroads, waste places, especially in sandy soil. From farther south.


SOLANUM CITRULLIFOLIUM A. Braun var. CITRULLIFOLIUM - . 2n = 24.


Waste places. From Texas, Mexico..


SOLANUM DULCAMARA Linnaeus - Climbing Nightshade. 2n = 24, (48), (72).


Moist thickets, clearings, streambanks, roadsides, waste places. From Eurasia, northern Africa. [S. DULCAMARA var. VILLOSISSIMUM Desvaux]


SOLANUM LYCOPERSICUM Linnaeus - Garden Tomato. 2n = 24, (36), (48).


Waste places, roadsides, railroads, shores, streambanks. From Mexico. [LYCOPERSICON ESCULENTUM Miller]


SOLANUM MELONGENA Linnaeus - Eggplant. 2n = 24, (36), (48).


Waste places. From Africa.


SOLANUM NIGRUM Linnaeus - European Black Nightshade. 2n = 24, (36), 48, 72, (96), (144).


Sea beaches, waste places. From Eurasia, northern Africa.


SOLANUM PHYSALIFOLIUM Rusby - . 2n = 24.


Waste places, field and woodland margins, roadsides. From South America. [S. SARACHOIDES misapplied]


SOLANUM PSEUDOCAPSICUM Linnaeus - Jerusalem-cherry. 2n = 24.


Waste places. From Mexico, Central America, Caribbean, South America.


Solanum ptychanthum Dunal - Eastern Black Nightshade. 2n = 24.


Woodlands, shores, thickets, waste places, usually moist soil. [S. americanum misapplied; S. nigrum misapplied]


SOLANUM ROSTRATUM Dunal - Buffalo-bur. 2n = 24.


Waste places, railroads, shores. From farther west. [S. CORNUTUM misapplied]


SOLANUM SISYMBRIIFOLIUM Lamarck - Sticky Nightshade. 2n = 24, (72).


Waste places. From South America.


SOLANUM TRIFLORUM Nuttall - . 2n = 24.


Waste places. From farther west.


SOLANUM TUBEROSUM Linnaeus - Potato. 2n = 24, (36), 48, (60), (72), (96).


Waste places, roadsides, railroads, fields. From western South America.


SOLANUM VILLOSUM Miller - . 2n = 48, (96).


Waste places. From southern Europe.



SOLIDAGO (Family: Asteraceae)


Solidago altissima Linnaeus subsp. altissima - 2n = (36), 54.


Clearings, fields, meadows, thickets, roadsides, waste places. [S. canadensis Linnaeus var. scabra (Muhlenberg ex Willdenow) Torrey & A. Gray]


Solidago arguta Aiton var. arguta - 2n = 18.


Open woods, clearings, roadsides.


Solidago bicolor Linnaeus - Silverrod. 2n = 18.


Dry, open, sterile soils, open woods, rocky slopes, roadsides.


Solidago brendae Semple - Brenda's Goldenrod. 2n = 18.


Roadsides.


Solidago caesia Linnaeus var. caesia - Blue-stem Goldenrod. 2n = 18.


Open or rich woods, woods margins, clearings, thickets.


Solidago canadensis Linnaeus var. canadensis - 2n = 18, (36).


Fields, roadsides, thickets, clearings, open woods.


Solidago canadensis Linnaeus var. hargeri Fernald - 2n = 18.


Fields, roadsides, thickets, clearings.


Solidago erecta Banks ex Pursh - Slender Goldenrod. 2n = 18.


Woods, sandy banks, roadsides.


Solidago flexicaulis Linnaeus - Zig-zag Goldenrod. 2n = 18, (27), 36, (90).


Rich woods, thickets.


Solidago gigantea Aiton - 2n = 18, 36, 54.


Damp thickets, meadows, stream banks, fields, swamps, open woods, roadsides. [S. gigantea var. leiophylla Fernald; S. gigantea var. serotina (Kuntze) Cronquist]


Solidago hispida Muhlenberg ex Willdenow - 2n = 18, (36).


Dry, open, rocky woods, usually in calcareous soil. [S. hispida var. lanata (Hooker) Fernald; S. bicolor Linnaeus var. concolor Torrey & A. Gray; S. bicolor var. lanata (Hooker) A. Gray]


Solidago juncea Aiton - Early Goldenrod. 2n = 18.


Fields, dry, open soil.


Solidago latissimifolia Miller - 2n = 18, 36, 54.


Swamps, meadows, low thickets. [S. elliottii Torrey & A. Gray var. elliottii; S. elliottii var. ascendans Fernald]


Solidago leiocarpa de Candolle - Cutler’s Alpine Goldenrod. 2n = 36.


Granitic alpine areas. [S. cutleri Fernald; S. multiradiata misapplied]


Solidago lepida de Candolle subsp. fallax (Fernald) Semple - 2n = 18.


Thickets, shores. [S. lepida var. molina Fernald]


Solidago macrophylla Banks ex Pursh - 2n = 18.


Shaded, rocky, mountain slopes. [S. macrophylla var. thyrsoidea (E. Meyer) Fernald]


Solidago nemoralis Aiton subsp. nemoralis - Gray Goldenrod. 2n = 18, 36.


Dry fields, open, sandy or gravelly soils, roadsides.


Solidago odora Aiton subsp. odora - Sweet Goldenrod. 2n = 18.


Dry, open woods, clearings, roadsides.


Solidago patula Muhlenberg ex Willdenow subsp. patula - Rough-leaved Goldenrod. 2n = 18.


Calcareous swamps, meadows, swales, wet woods and moist roadsides.


Solidago ptarmicoides (Torrey & Gray) B. Boivin - Snowy Aster. 2n = 18.


Dry, usually calcareous, ledges. [Aster ptarmicoides Torrey & Gray; Oligoneuron album (Nuttall) G.L. Nesom]


Solidago puberula Nuttall subsp. puberula - 2n = 18.


Dry, open woods, clearings, sandy or rocky shores of ponds and streams, roadsides.


Solidago rigida Linnaeus subsp. rigida - 2n = (18), 36.


Dry, open woods, clearings, thickets, near salt marshes, roadsides. [Oligoneuron rigidum (Linnaeus) Small]


Solidago rugosa Miller var. rugosa - 2n = 18, (36).


Moist, open soil, fields, thickets, borders of woods and streams. [S. rugosa var. villosa (Pursh) Fernald]


Solidago rugosa Miller var. sphagnophila C. Graves - 2n = 18, 54.


Swamps, meadows, wet thickets. [S. aestivalis E.P. Bicknell]


Solidago rugosa Miller subsp. aspera (Aiton) Cronquist - 2n = 18, 36.


Open woods, fields, thickets, roadsides. [S. aspera Aiton]


Solidago sempervirens Linnaeus subsp. sempervirens - Seaside Goldenrod. 2n = 18.


Salt marshes, seashores, tidal rivers, heavily-salted roadsides.


Solidago sempervirens Linnaeus subsp. mexicana (Linnaeus) Semple - Seaside Goldenrod. 2n = 18.


Salt marshes, seashores, tidal rivers, heavily-salted roadsides.


Solidago simplex Kunth var. monticola (Porter) G.S. Ringius - 2n = 36.


Dry, serpentine soils, rocky, granite barrens below alpine slopes. [S. glutinosa Nuttall var. randii (Porter) Cronquist (in part); S. randii (Porter) Britton (in part)]


Solidago simplex Kunth var. racemosa (Greene) G.S. Ringius - Riverbank Goldenrod. 2n = 36, 54.


Dry, usually calcareous rocks and ledges along rivers. [S. glutinosa Nuttall var. racemosa (Greene) Cronquist; S. racemosa Greene; S. randii (Porter) Britton (in part)]


Solidago speciosa Nuttall var. speciosa - 2n = 18, 36.


Fields, open woods, thickets, roadsides.


Solidago squarrosa Muhlenberg - Stout Goldenrod. 2n = 18.


Dry or rocky, open woods, rocky openings, thickets, fields, roadsides.


Solidago uliginosa Nuttall - Bog Goldenrod. 2n = 18, 36.


Bogs, swamps, meadows, marshes, fens, shores, usually sphagnous habitats. [S. uliginosa var. linoides (Torrey & A. Gray) Fernald; S. uliginosa var. terra-novae (Torrey & A. Gray) Fernald; S. purshii Porter]


Solidago ulmifolia Muhlenberg ex Willdenow var. ulmifolia - 2n = 18.


Dry, open or rocky woods, thickets, occasionally meadows.

Solidago hybrids

Solidago altissima Linnaeus X S. rugosa Miller var. rugosa - .



Solidago altissima Linnaeus X S. sempervirens Linnaeus var. sempervirens - .



Solidago arguta Aiton X S. bicolor Linnaeus - .



Solidago arguta Aiton X S. juncea Aiton - .



Solidago arguta Aiton X S. nemoralis Aiton - .



Solidago arguta Aiton X S. patula Muhlenberg ex Willdenow - .



Solidago X asperula Desfontaines (pro species) - .


[S. rugosa Miller var. rugosa X S. sempervirens Linnaeus subsp. sempervirens]


Solidago bicolor Linnaeus X S. caesia Linnaeus - .



Solidago bicolor Linnaeus X S. hispida Muhlenberg ex Willdenow - .



Solidago bicolor Linnaeus X S. nemoralis Aiton - .



Solidago bicolor Linnaeus X S. odora Aiton - .



Solidago bicolor Linnaeus X S. puberula Nuttall - .



Solidago bicolor Linnaeus X S. rugosa Miller var. rugosa - .



Solidago caesia Linnaeus X S. flexicaulis Linnaeus - .



Solidago caesia Linnaeus X S. juncea Aiton - .



Solidago caesia Linnaeus X S. rugosa Miller var. rugosa - .



Solidago X calcicola (Fernald) Fernald (pro species) - .


[S. macrophylla Banks ex Pursh X S. ?]


Solidago canadensis Linnaeus var. canadensis X S. gigantea Aiton - .



Solidago canadensis Linnaeus var. canadensis X S. juncea Aiton - .



Solidago canadensis Linnaeus var. canadensis X S. rugosa Miller var. rugosa - .



Solidago canadensis Linnaeus var. hargeri Fernald X S. rugosa Miller var. rugosa - .



Solidago gigantea Aiton X S. rugosa Miller var. rugosa - .



Solidago gigantea Aiton X S. sempervirens Linnaeus subsp. sempervirens - .



Solidago juncea Aiton X S. nemoralis Aiton - .



Solidago juncea Aiton X S. sempervirens Linnaeus subsp. sempervirens - .



Solidago latissimifolia Miller X S. rugosa Miller var. sphagnophila C. Graves - .



Solidago leiocarpa de Candolle X S. simplex Kunth var. monticola (Porter) G.S. Ringius - .



Solidago macrophylla Banks ex Pursh X S. rugosa Miller var. rugosa - .



Solidago nemoralis Aiton X S. sempervirens Linnaeus subsp. sempervirens - .



Solidago nemoralis Aiton X S. speciosa Nuttall - .



Solidago odora Aiton X S. rugosa Miller var. rugosa - .



Solidago rugosa Miller var. rugosa X S. ulmifolia Muhlenberg ex Willdenow - .




SONCHUS (Family: Asteraceae)


SONCHUS ARVENSIS Linnaeus subsp. ARVENSIS - Corn Sow-thistle. 2n = 18, 36, (40), (45), 54, (60), (64).


Waste places, fields, roadsides, shores, usually wet sites. From Eurasia, northern Africa.


SONCHUS ARVENSIS Linnaeus subsp. ULIGINOSUS (M. Bieberstein) Nyman - 2n = (27), 36.


Waste places, fields, roadsides, shores, usually wet sites. From Eurasia. [S. ARVENSIS var. GLABRESCENS Günther, Grabowski, & Wimmer; S. ULIGINOSUS M. Bieberstein]


SONCHUS ASPER (Linnaeus) Hill - Prickly Sow-thistle. 2n = 18, (36).


Waste places, roadsides, sea shores. From Eurasia, northern Africa.


SONCHUS OLERACEUS Linnaeus - Common Sow-thistle. 2n = (18), 32, (36), (64).


Waste places, fields, roadsides, sea shores. From Eurasia, northern Africa.



SORBARIA (Family: Rosaceae)


SORBARIA SORBIFOLIA (Linnaeus) A. Braun - False Spiraea. 2n = 18, 36.


Roadsides, waste places. From eastern Asia.



X SORBARONIA (Family: Rosaceae)


X SORBARONIA FALLAX (C.K. Schneider) C.K. Schneider - .


[Aronia melanocarpa (Michaux) Elliott X SORBUS AUCUPARIA Linnaeus; PYRUS X FALLAX (C.K. Schneider) Fernald]


X SORBARONIA HYBRIDA (Moench) C.K. Schneider - .


[Aronia arbutifolia (Linnaeus) Persoon X SORBUS AUCUPARIA Linnaeus; ARONIA HYBRIDA (Moench) Zabel; PYRUS HYBRIDA Moench; SORBUS X HYBRIDA (Moench) C.K. Schneider not Linnaeus – illegitimate name]


X Sorbaronia jackii Rehder - .


[Aronia X prunifolia (Marshall) Rehder X Sorbus americana Marshall; Pyrus X jackii (Rehder) Fernald]


X Sorbaronia monstrosa (Zabel) C.K. Schneider - .


[Aronia X arbutifolia (Linnaeus) Persoon X Sorbus americana Marshall]


X Sorbaronia sorbifolia (Poiret) C.K. Schneider - .


[Aronia melanocarpa (Michaux) Elliott X Sorbus americana Marshall; Aronia sargentii (Dippel) Zabel; Pyrus X mixta Fernald; Sorbus X sargentii Dippel; S. X sorbifolia (Poiret) Hedlund]



SORBUS (Family: Rosaceae)


Sorbus americana Marshall - American Mountain-ash. 2n = 34.


Cool, moist woods, mountain slopes. [Pyrus americana (Marshall) Sprengel]


SORBUS AUCUPARIA Linnaeus - European Mountain-ash. 2n = (30), 34, (51).


Woods, fields, roadsides, woodland borders, thickets. From Eurasia. [PYRUS AUCUPARIA (Linnaeus) Gaertner]


Sorbus decora (Sargent) C.K. Schneider - Northern Mountain-ash. 2n = 34, 68.


Wet woods, high mountain slopes, freshwater shores. [S. decora var. groenlandica (C.K. Schneider) G.N. Jones; Pyrus decora (Sargent) Hyland; P. decora var. groenlandica (C.K. Schneider) Fernald]


SORBUS INTERMEDIA (Ehrhart) Persoon - Swedish Whitebeam. 2n = 68.


Roadsides. From Europe. [PYRUS INTERMEDIA Ehrhart]



SORGHASTRUM (Family: Poaceae)


Sorghastrum nutans (Linnaeus) Nash - Indian Grass. 2n = (20), 40, (80).


Dry fields, roadsides, rocky shores of rivers.



SORGHUM (Family: Poaceae)


SORGHUM BICOLOR (Linnaeus) Moench - Sorghum. 2n = (10), 20, (40).


Waste places. From Africa. [S. VULGARE Persoon]


SORGHUM HALEPENSE (Linnaeus) Persoon - Johnson Grass. 2n = (18), (20), 40, (60).


Waste places. From the Mediterranean.



SPARGANIUM (Family: Typhaceae)


Sparganium americanum Nuttall - . 2n = ?


Muddy shores, shallow water.


Sparganium androcladum (Engelmann) Morong - . 2n = ?


Muddy shores, marshes, shallow water.


Sparganium angustifolium Michaux - . 2n = 30.


Shallow or deep water, shores. [S. multipedunculatum (Morong) Rydberg]


Sparganium emersum Rehmann - . 2n = 30.


Muddy shores, marshes, shallow water [S. chlorocarpum Rydberg; S. chlorocarpum var. acaule (Beeby) Fernald]


Sparganium eurycarpum Engelmann - . 2n = 30.


Mostly basic, muddy shores, marshes, shallow water.


Sparganium fluctuans (Morong) B.L. Robinson - . 2n = ?


Non-basic lakes and ponds.


Sparganium natans Linnaeus - . 2n = 30.


Shallow pools, streams, shores, bogs. [S. minimum Fries ex Wallroth]


Sparganium hybrids

Sparganium americanum Nuttall X S. fluctuans (Morong) B.L. Robinson - .



Sparganium angustifolium Michaux X S. emersum Rehmann - .




SPARTINA (Family: Poaceae)


Spartina alterniflora Loiseleur - Smooth Cordgrass. 2n = (40), (56), (60), 62.


Salt marshes, tidal shores. [S. alterniflora var. pilosa (Merrill) Fernald]


Spartina cynosuroides (Linnaeus) Roth - Big Cordgrass. 2n = 40, 42.


Salt marshes. [S. cynosuroides var. polystachya (Michaux) Beal]


Spartina patens (Aiton) Muhlenberg - Saltmeadow Cordgrass. 2n = (28), 40.


Salt marshes. [S. patens var. monogyna (M.A. Curtis) Fernald]


Spartina pectinata Link - Prairie Cordgrass. 2n = (28), 40, (80).


Shores, meadows, lowlands. [S. pectinata var. suttiei (Farwell) Fernald]


SPARTINA hybrid

Spartina X caespitosa A.A. Eaton (pro species) - .


Salt marsh borders, beaches. [S. patens (Aiton) Muhlenberg X S. pectinata Link; S. patens var. caespitosa (A.A. Eaton) Hitchcock]



SPERGULA (Family: Caryophyllaceae)


SPERGULA ARVENSIS Linnaeus - Corn Spurrey. 2n = 18, (36).


Roadsides, fallow fields. From Eurasia. [S. ARVENSIS var. SATIVA (Boenninghausen) Mertens & W.D.J. Koch]


SPERGULA MORISONII Boreau - Pearlwort Spurrey. 2n = 18.


Sandy roadsides, disturbed ground. From Europe.


SPERGULA PENTANDRA Linnaeus - Wingstem Spurrey. 2n = 18.


Sandy fields, disturbed ground. From Eurasia, northern Africa.



SPERGULARIA (Family: Caryophyllaceae)


Spergularia canadensis (Persoon) G. Don var. canadensis - Northern Sand-spurrey. 2n = 36.


Salt marshes, tidal shores.


SPERGULARIA RUBRA (Linnaeus) J. Presl & C. Presl - Red Sand-spurrey. 2n = (18), (27), 36.


Dry, sandy, gravelly roadsides or disturbed places. From Eurasia.


Spergularia salina J. Presl & C. Presl - Salt-marsh Sand-spurrey. 2n = (18), 36.


Salt marshes, saline or brackish soils. [S. marina (Linnaeus) Besser var. marina; S. marina var. leiosperma (Kindberg) Gürke)]



SPHAERALCEA (Family: Malvaceae)


SPHAERALCEA MENDOCINA (Philippi) K. Schumann - . 2n = 30.


Wool waste. From South America.



SPHENOPHOLIS (Family: Poaceae)


Sphenopholis intermedia Rydberg (Rydberg) - . 2n = 14.


Meadows, shores, damp slopes. [S. obtusata (Michaux) Scribner var. major (Torrey) Erdman]


Sphenopholis nitida (Biehler) Scribner - . 2n = 14.


Rich, rocky woods.


Sphenopholis obtusata (Michaux) Scribner - Prairie Wedgegrass. 2n = 14.


Wood borders, shores, dry ledges. [S. obtusata var. lobata (Trinius) Scribner ex B.L. Robinson; S. obtusata var. pubescens (Scribner & Merrill) Scribner ex B.L. Robinson]


Sphenopholis pensylvanica (Linnaeus) Hitchcock - Swamp Oats. 2n = 14.


Meadows. [Trisetum pensylvanicum (Linnaeus) P. Beauvois ex Roemer & Schultes]



SPINACIA (Family: Amaranthaceae)


SPINACIA OLERACEA Linnaeus - Spinach. 2n = 12, (18), (24).


Waste places. From Eurasia, northern Africa.



SPIRAEA (Family: Rosaceae)


Spiraea alba Du Roi var. alba - Hairy Meadowsweet. 2n = 36.


Swamps, low, moist, open ground.


Spiraea alba Du Roi var. latifolia (Aiton) Dippel - Smooth Meadowsweet. 2n = 36, 54.


Low, open ground, alpine areas. [S. alba var. septentrionalis (Fernald) Fosberg; S. latifolia (Aiton) Borkhausen var. latifolia; S. latifolia var. septentrionalis Fernald; S. septentrionalis (Fernald) Á. Löve & D. Löve]


SPIRAEA CHAMAEDRYFOLIA Linnaeus - Germander Meadowsweet. 2n = (18), (32), 36.


Roadsides. From Eurasia. [S. CHAMAEDRYFOLIA var. ULMIFOLIA (Scopoli) Maximowicz]


SPIRAEA HYPERICIFOLIA Linnaeus subsp. OBOVATA (Waldstein & Kitaibel ex Willdenow) Dostál - Iberian Spiraea. 2n = ?


Roadside in dry calcareous, sandy soil. From Europe.


SPIRAEA JAPONICA Linnaeus (son) var. FORTUNEI (Planchon) Rehder - Japanese Spiraea. 2n = 36.


Roadsides, railroads, thickets. From eastern Asia.


SPIRAEA NIPPONICA Maximowicz - 2n = ?


Shrubland at edge of lowland plain. From Japan.


SPIRAEA PRUNIFOLIA Siebold & Zuccarini - Bridalwreath Spiraea. 2n = 18.


Roadsides, waste places, rocky knolls. From eastern Asia.


SPIRAEA THUNBERGII Siebold ex Blume - Baby’s-breath Spiraea. 2n = 18.


Dry, sandy, fields, open woods, clearings, roadsides, shores. From China.


Spiraea tomentosa Linnaeus - Hardhack. 2n = 36.


Low, open, often moist, acidic soil, fields. [S. tomentosa var. rosea (Rafinesque) Fernald]

Spiraea hybrid

SPIRAEA X VANHOUTTEI (Briot) Carrière (pro species) - .


[parentage uncertain; origin from cultivation]



SPIRANTHES (Family: Orchidaceae)


Spiranthes casei Catling & Cruise var. casei - . 2n = ?


Sandy, acid soils, roadsides, fields.


Spiranthes cernua (Linnaeus) Richard - Nodding Ladies'-tresses. 2n = 30, 45, 60.


Damp banks, meadows, bogs, shores, low thickets, open, moist sandy places.


Spiranthes lacera (Rafinesque) Rafinesque var. lacera - Northern Slender Ladies'-tresses. 2n = 30.


Open sandy places.


Spiranthes lacera (Rafinesque) Rafinesque var. gracilis (Bigelow) Luer - Southern Slender Ladies'-tresses. 2n = 30.


Sterile, open soils, thickets, or open woods. [S. gracilis (Bigelow) L.C. Beck]


Spiranthes lucida (H.H. Eaton) Ames - . 2n = 44.


Damp, rocky shores, meadows, rich, damp thickets, usually in basic soils.


Spiranthes ochroleuca (Rydberg) Rydberg - . 2n = 30.


Sterile fields, dry barrens, rocky slopes, open woods, roadsides. [S. cernua (Linnaeus) Richard var. ochroleuca (Rydberg) Ames]


Spiranthes romanzoffiana Chamisso - Hooded Ladies'-tresses. 2n = 30, 44, 60.


Swampy places, often along rivers and ponds, thickets.


Spiranthes tuberosa Rafinesque - Little Ladies'-tresses. 2n = ?


Dry, sandy fields, woodland borders, cemeteries, roadsides. [S. tuberosa var. grayi (Ames) Fernald]


Spiranthes vernalis Engelmann & A. Gray - Spring Ladies'-tresses. 2n = 30.


Grasslands, sandy fields, clearings.


Spiranthes hybrids

Spiranthes X eamesii P.M. Brown - .


[S. lacera (Rafinesque) Rafinesque gracilis (Bigelow) Luer X S. tuberosa Rafinesque]


Spiranthes X intermedia Ames - .


[S. lacera (Rafinesque) Rafinesque var. lacera X S. vernalis Engelmann & A. Gray]


Spiranthes X simpsonii Catling & Sheviak - .


[Spiranthes lacera (Rafinesque) Rafinesque var. lacera X S. romanzoffiana Chamisso]



SPIRODELA (Family: Araceae)


Spirodela polyrhiza (Linnaeus) Schleiden - Water Flaxseed. 2n = (30), (38), 40, (42), (50), (80).


Surface of quiet water of lakes, ponds, ditches and streams; muddy shores.



SPOROBOLUS (Family: Poaceae)


Sporobolus clandestinus (Biehler) Hitchcock - . 2n = 28, 54.


Dry, sandy or rocky soil.


Sporobolus compositus (Poiret) Merrill var. compositus - . 2n = 54, (ca. 88), (108).


Dry, sandy, open soil. [S. asper (P. Beauvois) Kunth]


Sporobolus compositus (Poiret) Merrill var. drummondii (Trinius) Kartesz & Gandhi - . 2n = ?


River ledges. [S. drummondii (Trinius) Vasey]


SPOROBOLUS CONTRACTUS Hitchcock - Spike Dropseed. 2n = 36.


Sandy soil, waste places. From farther west. [S. CRYPTANDRUS (Torrey) A. Gray var. STRICTUS Scribner]


Sporobolus cryptandrus (Torrey) A. Gray - Sand Dropseed. 2n = (18), (36), 38, (72).


Sandy soil, usually near sea shores.


Sporobolus heterolepis (A. Gray) A. Gray - Prairie Dropseed. 2n = 72.


Dry trap (limestone or serpentine).


Sporobolus neglectus Nash - . 2n = 36.


Dry open soil.


Sporobolus vaginiflorus (Torrey ex A. Gray) Alph. Wood var. vaginiflorus - Poverty Grass. 2n = 54.


Roadsides, sandy fields, dry, open, sterile soil. [S. vaginiflorus var. inaequalis Fernald]



STACHYS (Family: Lamiaceae)


STACHYS ANNUA (Linnaeus) Linnaeus - . 2n = 34.


Waste places. From Eurasia.


STACHYS ARVENSIS (Linnaeus) Linnaeus - Staggerweed. 2n = 10.


Waste places. From Eurasia, northwestern Africa.


STACHYS ASPERA Michaux - . 2n = ca. 60, ca. 64, 68, 78, 83, 102.


Roadsides. From farther south and west. [S. HYSSOPIFOLIA Michaux var. AMBIGUA A. Gray]


STACHYS BYZANTINA K. Koch - Lamb’s-ears. 2n = 30, (34).


Waste places, fields, swamp margins. From Caucasus region.


STACHYS GERMANICA Linnaeus - . 2n = 30.


Waste places. From Eurasia, northwestern Africa.


Stachys hispida Pursh - 2n = 64, 68.


Meadows, swamps, low woodlands, shores, damp thickets. [S. tenuifolia Willdenow var. hispida (Pursh) Fernald; S. tenuifolia Willdenow var. platyphylla misapplied]


Stachys hyssopifolia Michaux - . 2n = 34.


Sandy pond shores.


STACHYS PALUSTRIS Linnaeus - Woundwort. 2n = (34), (48), 64, (66), (68), (96), (97), 102, (103), (1040.


Shores, damp thickets, wet roadsides, low meadows, waste places. From Eurasia. [S. PALUSTRIS var. ELLIPTICA Clos; S. PALUSTRIS var. SEGETUM (Mutel) Grognier]


Stachys pilosa Nuttall var. pilosa - . 2n = 64, 68.


Shores, meadows, fields, low grounds. [S. palustris Linnaeus var. homotricha Fernald; S. palustris var. nipigonensis Jennings; S. palustris var. pilosa (Nuttall) Fernald]


STACHYS PILOSA Nuttall var. ARENICOLA (Britton) G.A. Mulligan & D.B. Munro - 2n = 68.


Wet grounds. From farther west.



STAPHYLEA (Family: Staphyleaceae)


Staphylea trifolia Linnaeus - American Bladdernut. 2n = 78.


Rich woodland margins, thickets, roadsides.



STELLARIA (Family: Caryophyllaceae)


Stellaria alsine Grimm - Bog Chickweed. 2n = 24, (26), (36).


Brooksides, springy places, wet ditches.


Stellaria borealis Bigelow subsp. borealis - Northern Stitchwort. 2n = 52.


Springy and other wet places. [S. calycantha (Ledebour) Bongard var. calycantha misapplied; S. calycantha var. floribunda (Fernald) Fernald; S. calycantha var. isophylla (Fernald) Fernald]


STELLARIA COREI Shinners - Tennessee Chickweed. 2n = 60.


Rocky woods. From farther west. [S. pubera Michaux var. silvatica (Béguinot) Weatherby]


STELLARIA GRAMINEA Linnaeus - Common Stitchwort. 2n = 26, 39, 52.


Fields, roadsides. From Europe.


STELLARIA HOLOSTEA Linnaeus - Greater Stitchwort. 2n = 26.


Dry woods, roadsides. From Eurasia.


Stellaria humifusa RottbØll - Salt-marsh Stitchwort. 2n = 26.


Salt marshes.


Stellaria longifolia Muhlenberg ex Willdenow - Long-leaved Stitchwort. 2n = 26.


River thickets, meadows.


STELLARIA MEDIA (Linnaeus) Villars - Common Chickweed. 2n = (18), (26), (28), 40, 42, 44.


Waste places, open woodland. From Europe.


STELLARIA PUBERA Michaux - Star Chickweed. 2n = 30, 32.


Rich, deciduous woods, shaded rocky slopes. From farther south and west.

Stellaria hybrid

Stellaria borealis Bigelow X S. longifolia Muhlenberg ex Willdenow - .




STENANTHIUM (Family: Melanthiaceae)


Stenanthium gramineum (Ker Gawler) Morong - Featherbells. 2n = 20.


Pond shores.



STREPTOPUS (Family: Liliaceae)


Streptopus amplexifolius (Linnaeus) de Candolle - Twisted Stalk. 2n = 16, 32.


Rich, damp woods and thickets. [S. amplexifolius var. americanus Schultes & Schultes (son)]


Streptopus lanceolatus (Aiton) Reveal - Rose Mandarin. 2n = 16, (32), (48).


Rich, damp, cool woods and thickets. [S. roseus Michaux var. longipes (Fernald) Fassett; S. roseus var. perspectus Fassett]

Streptopus hybrid

Streptopus X oreopolus Fernald (pro species) - .


Subalpine woods and meadows. [S. amplexifolius (Linnaeus) de Candolle X S. lanceolatus (Aiton) Reveal; S. amplexifolius var. oreopolus (Fernald) Fassett]



STROPHOSTYLES (Family: Fabaceae)


Strophostyles helvola (Linnaeus) Elliott - Trailing Wild Bean. 2n = 22.


Sandy or gravelly soil, usually near coast, shores, marsh margins, railroads, fields, roadsides.


STROPHOSTYLES LEIOSPERMA (Torrey & A. Gray) Piper - . 2n = ?


Old gravel or sand pits. From farther west.


Strophostyles umbellata (Muhlenberg ex Willdenow) Britton - Perennial Wild Bean. 2n = 22, (44).


Beaches.



STUCKENIA (Family: Potamogetonaceae)


Stuckenia filiformis (Persoon) Börner subsp. alpina (Blytt) R.R. Haynes, Les & M. Král - . 2n = 78.


Highly alkaline water of cold springs and lakes. [Potamogeton filiformis Persoon var. borealis (Rafinesque) H. St. John; P. filiformis var. macounii (Morong ex Macoun) Morong]


Stuckenia filiformis (Persoon) Börner subsp. occidentalis (J.W. Robbins) R.R. Haynes, Les & M. Král - . 2n = ?


Highly alkaline water of cold streams.


Stuckenia pectinata (Linnaeus) Börner - Sago. 2n = (42), (ca. 66), 78, (84), (86).


Brackish or alkaline waters. [Potamogeton pectinatus Linnaeus]



SUAEDA (Family: Amaranthaceae)


Suaeda calceoliformis (Hooker) Moquin-Tandon - Horned Sea-blite. 2n = 54.


Salt marshes, sea beaches. [S. americana (Persoon) Fernald]


Suaeda linearis (Elliott) Moquin-Tandon - Southern Sea-blite. 2n = 30, 54.


Salt marshes, sea beaches.


Suaeda maritima (Linnaeus) Dumortier - White Sea-blite. 2n = 18, 36, (72).


Salt marshes, sea beaches. [S. richii Fernald]



SUBULARIA (Family: Brassicaceae)


Subularia aquatica Linnaeus subsp. americana G.A. Mulligan & Calder - Awlwort. 2n = 28, 30.


Submersed at sandy lake shores.



SUCCISELLA (Family: Caprifoliaceae)


SUCCISELLA INFLEXA (Kluk) Beck - . 2n = (16), 20.


Low, swampy ground, river meadows. From Europe. [SUCCISA AUSTRALIS (Wulfen) Reichenbach]



SYMPHORICARPOS (Family: Caprifoliaceae)


Symphoricarpos albus (Linnaeus) S.F. Blake var. albus - Common Snowberry. 2n = (36), 54.


Wooded, calcareous ledges.


SYMPHORICARPOS ALBUS (Linnaeus) S.F. Blake var. LAEVIGATUS (Fernald) S.F. Blake - . 2n = 72.


Roadsides, wooded hillsides, usually near habitation. From farther west.


SYMPHORICARPOS OCCIDENTALIS Hooker - Wolfberry. 2n = 36.


Waste places. From farther west.


SYMPHORICARPOS ORBICULATUS Moench - Coralberry. 2n = 18.


Roadsides, fencerows, waste places, meadows. From farther west and south.



SYMPHYOTRICHUM (Family: Asteraceae)


Symphyotrichum anticostense (Fernald) G.L. Nesom - . 2n = 80.


Gravelly, river shores. [Aster anticostensis Fernald]


Symphyotrichum boreale (Torrey & A. Gray) Á. Löve & D. Löve - Northern Bog Aster. 2n = 16, 32, 48, 64.


Bogs, swamps, shores, mostly in calcareous areas. [Aster borealis (Torrey & A. Gray) Provancher; A. junciformis Rydberg]


SYMPHYOTRICHUM CILIATUM (Ledebour) G.L. Nesom - Rayless Aster. 2n = 14, (18).


Roadsides, waste places. From farther west. [ASTER BRACHYACTIS S.F. Blake]


Symphyotrichum ciliolatum (Lindley) Á. Löve & D. Löve - 2n = (24), 48, (72).


Dry woods, thickets, shores, clearings, roadsides. [Aster ciliolatus Lindley]


Symphyotrichum concolor (Linnaeus) G.L. Nesom var. concolor - Eastern Silvery Aster. 2n = 8, 16.


Dry, open, sandy woods, fields and barrens, roadsides. [Aster concolor Linnaeus]


Symphyotrichum cordifolium (Linnaeus) G.L. Nesom - Common Blue Wood Aster. 2n = 16, (18), 32, (48).


Thickets, open woods, clearings, fields, roadsides, often in moist soil. [Aster cordifolius Linnaeus var. cordifolius; A. cordifolius var. furbishiae Fernald; A. cordifolius var. polycephalus Porter; A. cordifolius var. racemiflorus Fernald; A. lowrieanus Porter var. lowrieanus; A. lowrieanus var. lanceolatus (Porter) Porter; A. sagittifolius Wedemeyer ex Willdenow]


Symphyotrichum dumosum (Linnaeus) G.L. Nesom - Rice-button Aster. 2n = (8), 16, 32, 64.


Dry, open woods, fields, thickets, roadsides. [Aster dumosus Linnaeus var. dumosus; A. dumosus var. cordifolius (Michaux) Torrey & A. Gray; A. dumosus var. strictior Torrey & A. Gray; A. dumosus var. subulifolius Torrey & A. Gray]


Symphyotrichum ericoides (Linnaeus) G.L. Nesom var. ericoides - White Heath Aster. 2n = 10, 20, (32).


Dry fields and clearings, dry, open woods, waste places, roadsides, sometimes in moist, open, sandy sites. [Aster ericoides Linnaeus]


SYMPHYOTRICHUM FRONDOSUM (Nuttall) G.L. Nesom - 2n = 14, 16.


Wool waste. From farther west. [Aster frondosus (Nuttall) Torrey & A. Gray]


Symphyotrichum laeve (Linnaeus) Á. Löve & D. Löve var. laeve - Smooth Aster. 2n = (24), 48, (ca. 56).


Dry fields, open woods, roadsides, dry, open, sites. [Aster laevis Linnaeus]


Symphyotrichum lanceolatum (Willdenow) G.L. Nesom var. lanceolatum - Panicled Aster. 2n = 32, (40), 48, (56), 64.


Meadows, wet thickets, shores. [Aster lanceolatus Willdenow var. lanceolatus; A. lanceolatus var. simplex (Willdenow) A.G. Jones; A. simplex Willdenow var. simplex; A. simplex var. ramosissimus (Torrey & A. Gray) Cronquist]


Symphyotrichum lanceolatum (Willdenow) G.L. Nesom var. interior (Wiegand) G.L. Nesom - 2n = 48, 64.


Gravelly or rocky shores, often calcareous. [Aster lanceolatus Willdenow var. interior Semple & Chmielewski; A. simplex Willdenow var. interior (Wiegand) Cronquist]


Symphyotrichum lanceolatum (Willdenow) G.L. Nesom var. latifolium (Semple & Chmielewski) G.L. Nesom - 2n = 48, 64.


Thickets, woods margins, shores.


Symphyotrichum lateriflorum (Linnaeus) Á. Löve & D. Löve - Calico Aster. 2n = 16, 32, (48), (64).


Woods, swamps, fields, thickets, clearings, shores, meadows, moist ledges, roadsides. [Aster lateriflorus (Linnaeus) Britton var. lateriflorus; A. lateriflorus var. angustifolius Wiegand; A. lateriflorus var. pendulus (Aiton) E.S. Burgess; A. lateriflorus var. tenuipes Wiegand; A. vimineus Lamarck]


Symphyotrichum novae-angliae (Linnaeus) G.L. Nesom - New England Aster. 2n = 10, (20).


Fields, damp thickets, shores, meadows, clearings, open woods, roadsides. [Aster novae-angliae Linnaeus]


Symphyotrichum novi-belgii (Linnaeus) G.L. Nesom var. novi-belgii - New York Aster. 2n = 48, (54), 64, 80.


Swamps, salt marshes, damp thickets, shores, sea beaches, moist woods, meadows, roadsides. [Aster foliaceus misapplied; A. foliaceus Lindley ex de Candolle var. arcuans Fernald; A. johannensis Fernald var. johannensis; A. longifolius Lamarck; A. novi-belgii Linnaeus var. novi-belgii]


Symphyotrichum novi-belgii (Linnaeus) G.L. Nesom var. elodes (Torrey & A. Gray) G.L. Nesom - 2n = 48.


Salt marshes, pine barrens. [Aster novi-belgii Linnaeus var. elodes (Torrey & A. Gray) A. Gray]


Symphyotrichum novi-belgii (Linnaeus) G.L. Nesom var. villicaule (A. Gray) Labrecque & Brouillet - 2n = 48.


Gravelly or rocky, river shores, ledges. [Aster johannensis Fernald var. villicaulis (A. Gray) Fernald]


Symphyotrichum ontarionis (Wiegand) G.L. Nesom var. ontarionis - 2n = 32.


Thickets, meadows, alluvial woods and shores, often in calcareous soil. [Aster ontarionis Wiegand]


Symphyotrichum patens (Aiton) G.L. Nesom var. patens - Late Purple Aster. 2n = 10, 20, (50).


Dry fields, open woods, clearings and roadsides. [Aster patens Aiton var. patens]


Symphyotrichum pilosum (Willdenow) G.L. Nesom var. pilosum - Frost Aster. 2n = (24), 32, (40), 48.


Dry fields, thickets, open woods, clearings and roadsides, often in sandy soil. [Aster pilosus Willdenow var. pilosus]


Symphyotrichum pilosum (Willdenow) G.L. Nesom var. pringlei (A. Gray) G.L. Nesom - 2n = 48, (56).


Rocky, gravelly or sandy soil, often calcareous. [Aster pilosus Willdenow var. demotus S.F. Blake; A. pilosus var. pringlei (A. Gray) S.F. Blake]


Symphyotrichum praealtum (Poiret) G.L. Nesom - Willow Aster. 2n = 32, 48, 64.


Low thickets and woods, meadows. [Aster praealtus Poiret var. praealtus; A. praealtus var. angustior Wiegand]


Symphyotrichum prenanthoides (Muhlenberg ex Willdenow) G.L. Nesom - Zigzag Aster. 2n = 32.


Moist thickets and fields, rich woods, shores, roadsides. [Aster prenanthoides Muhlenberg ex Willdenow]


Symphyotrichum puniceum (Linnaeus) Á. Löve & D. Löve var. puniceum - Swamp Aster. 2n = 16, (32), (36).


Low thickets, woods, swamps, meadows, shores, ditches, roadsides. [S. firmum (Nees) G.L. Nesom; Aster puniceus Linnaeus var. puniceus; A. puniceus var. compactus Fernald; A. puniceus var. firmus (Nees) Torrey & A. Gray; A. puniceus var. oligocephalus Fernald; A. puniceus var. perlongus Fernald]


Symphyotrichum racemosum (Elliott) G.L. Nesom - Small White Aster. 2n = 16, 32.


Fields, meadows, shores, woods, clearings, roadsides. [Aster vimineus misapplied; A. vimineus Lamarck var. subdumosus Wiegand]


Symphyotrichum subulatum (Michaux) G.L. Nesom var. subulatum - Annual Saltmarsh Aster. 2n = 10.


Salt marshes, salted highways. [Aster subulatus Michaux var. subulatus; A. subulatus var. euroauster Fernald & Griscom]


Symphyotrichum tenuifolium (Linnaeus) G.L. Nesom var. tenuifolium - Perennial Saltmarsh Aster. 2n = 10, (20).


Salt marshes, tidal shores. [Aster tenuifolius Linnaeus]


Symphyotrichum tradescantii (Linnaeus) G.L. Nesom - Shore Aster. 2n = 16, 32.


Rocky or gravelly, freshwater shores, waste places. [Aster tradescantii Linnaeus]


Symphyotrichum undulatum (Linnaeus) G.L. Nesom - 2n = 16, (18), 32, (36).


Dry fields and open, deciduous woods, clearings, fields, roadsides. [Aster undulatus Linnaeus; A. undulatus var. loriformis E.S. Burgess]


Symphyotrichum urophyllum (Lindley ex de Candolle) G.L. Nesom - 2n = 16.


Dry open, woods, clearings and fields. [Aster sagittifolius misapplied]

Symphyotrichum hybrids

Symphyotrichum X amethystinum (Nuttall (pro species)) G.L. Nesom - .


[S. ericoides (Linnaeus) G.L. Nesom X S. novae-angliae (Linnaeus) G.L. Nesom; Aster X amethystinus Nuttall (pro species)]


Symphyotrichum ciliolatum (Lindley) Á. Löve & D. Löve X S. prenanthoides (Muhlenberg ex Willdenow) G.L. Nesom - .



Symphyotrichum ciliolatum (Lindley) Á. Löve & D. Löve X S. puniceum (Linnaeus) Á. Löve & D. Löve - .



Symphyotrichum cordifolium (Linnaeus) G.L. Nesom X S. ericoides (Linnaeus) G.L. Nesom - .



Symphyotrichum cordifolium (Linnaeus) G.L. Nesom X S. lateriflorum (Linnaeus) Á. Löve & D. Löve - .



Symphyotrichum cordifolium (Linnaeus) G.L. Nesom X S. novi-belgii (Linnaeus) G.L. Nesom var. novi-belgii - .



Symphyotrichum cordifolium (Linnaeus) G.L. Nesom X S. pilosum (Willdenow) G.L. Nesom var. pringlei (A. Gray) G.L. Nesom - .



Symphyotrichum cordifolium (Linnaeus) G.L. Nesom X S. puniceum (Linnaeus) Á. Löve & D. Löve - .



Symphyotrichum cordifolium (Linnaeus) G.L. Nesom X S. undulatum (Linnaeus) G.L. Nesom - .



Symphyotrichum dumosum (Linnaeus) G.L. Nesom X S. lateriflorum (Linnaeus) Á. Löve & D. Löve - .



Symphyotrichum dumosum (Linnaeus) G.L. Nesom X S. puniceum (Linnaeus) Á. Löve & D. Löve - .



Symphyotrichum dumosum (Linnaeus) G.L. Nesom X S. racemosum (Elliott) G.L. Nesom - .



Symphyotrichum dumosum (Linnaeus) G.L. Nesom X S. tradescantii (Linnaeus) G.L. Nesom - .



Symphyotrichum ericoides (Linnaeus) G.L. Nesom X S. novi-belgii (Linnaeus) G.L. Nesom var. novi-belgii - .



Symphyotrichum ericoides (Linnaeus) G.L. Nesom X S. undulatum (Linnaeus) G.L. Nesom - .



Symphyotrichum X gravesii (E.S. Burgess (pro species)) G.L. Nesom - .


[S. cordifolium (Linnaeus) G.L. Nesom X S. laeve (Linnaeus) Á. Löve & D. Löve or S. dumosum (Linnaeus) G.L. Nesom X S. laeve (Linnaeus) Á. Löve & D. Löve; Aster X gravesii E.S. Burgess (pro species)]


Symphyotrichum laeve (Linnaeus) Á. Löve & D. Löve X S. lanceolatum (Willdenow) G.L. Nesom var. lanceolatum - .



Symphyotrichum laeve (Linnaeus) Á. Löve & D. Löve X S. racemosum (Elliott) G.L. Nesom - .



Symphyotrichum laeve (Linnaeus) Á. Löve & D. Löve X S. undulatum (Linnaeus) G.L. Nesom - .



Symphyotrichum lanceolatum (Willdenow) G.L. Nesom var. lanceolatum X S. novae-angliae (Linnaeus) G.L. Nesom - .



Symphyotrichum lanceolatum (Willdenow) G.L. Nesom var. lanceolatum X S. novi-belgii (Linnaeus) G.L. Nesom var. novi-belgii - .



Symphyotrichum lanceolatum (Willdenow) G.L. Nesom var. lanceolatum X S. pilosum (Willdenow) G.L. Nesom var. pringlei (A. Gray) G.L. Nesom - .



Symphyotrichum lanceolatum (Willdenow) G.L. Nesom var. lanceolatum X S. praealtum (Poiret) G.L. Nesom - .



Symphyotrichum lanceolatum (Willdenow) G.L. Nesom var. lanceolatum X S. puniceum (Linnaeus) Á. Löve & D. Löve - .



Symphyotrichum lanceolatum (Willdenow) G.L. Nesom var. lanceolatum X S. tradescantii (Linnaeus) G.L. Nesom - .



Symphyotrichum lateriflorum (Linnaeus) Á. Löve & D. Löve X S. novi-belgii (Linnaeus) G.L. Nesom var. novi-belgii - .



Symphyotrichum lateriflorum (Linnaeus) Á. Löve & D. Löve X S. puniceum (Linnaeus) Á. Löve & D. Löve - .



Symphyotrichum lateriflorum (Linnaeus) Á. Löve & D. Löve X S. racemosum (Elliott) G.L. Nesom - .



Symphyotrichum lateriflorum (Linnaeus) Á. Löve & D. Löve X S. undulatum (Linnaeus) G.L. Nesom - .



Symphyotrichum novi-belgii (Linnaeus) G.L. Nesom var. novi-belgii X S. pilosum (Willdenow) G.L. Nesom var. pilosum - .



Symphyotrichum novi-belgii (Linnaeus) G.L. Nesom var. novi-belgii X S. praealtum (Poiret) G.L. Nesom - .



Symphyotrichum novi-belgii (Linnaeus) G.L. Nesom var. novi-belgii X S. prenanthoides (Muhlenberg ex Willdenow) G.L. Nesom - .



Symphyotrichum novi-belgii (Linnaeus) G.L. Nesom var. novi-belgii X S. puniceum (Linnaeus) Á. Löve & D. Löve - .



Symphyotrichum pilosum (Willdenow) G.L. Nesom var. pilosum X S. undulatum (Linnaeus) G.L. Nesom - .



Symphyotrichum X tardiflorum (Linnaeus) Greuter, M.V. Aghababian & Wagenitz - .


[S. cordifolium (Linnaeus) G.L. Nesom X S. puniceum (Linnaeus) Á. Löve & D. Löve; Aster tardiflorus Linnaeus]


Symphyotrichum X woldenii (Rydberg (pro species)) G.L. Nesom - .


[S. laeve (Linnaeus) Á. Löve & D. Löve X S. praealtum (Poiret) G.L. Nesom; S. novi-belgii (Linnaeus) G.L. Nesom var. litoreum (A. Gray) G.L. Nesom; Aster novi-belgii Linnaeus var. litoreus A. Gray; Aster X woldenii Rydberg (pro species); However, the parentage for this hybrid is in doubt.]




SYMPHYTUM (Family: Boraginaceae)


SYMPHYTUM ASPERUM Lepechin - Prickly Comfrey. 2n = 32, (40), (45).


Roadsides, waste places. From the Caucasus region.


SYMPHYTUM OFFICINALE Linnaeus - Common Comfrey. 2n = 24, (36), 40, (45), 48, (54), (56).


Roadsides, waste places. From Eurasia.


SYMPHYTUM TUBEROSUM Linnaeus - . 2n = (18), (32), (44), 64, 96, (120), (ca. 128), (144).


Ditches, fields. From Europe.

Symphytum hybrid

SYMPHYTUM X UPLANDICUM Nyman (pro species) - .


[S. ASPERUM Lepechin X S. OFFICINALE Linnaeus]



SYMPLOCARPUS (Family: Araceae)


Symplocarpus foetidus (Linnaeus) Salisbury ex W.P.C. Barton - Skunk Cabbage. 2n = (26), (30), 60.


Swamps, damp thickets and woods, wet meadows, shores.



SYMPLOCOS (Family: Symplocaceae)


SYMPLOCOS PANICULATA Miquel - Sapphire-berry. 2n = 22.


Swamp margins. From Asia.



SYRINGA (Family: Oleaceae)


SYRINGA RETICULATA (Blume) H. Hara subsp. RETICULATA - Japanese Tree Lilac. 2n = 46.


Roadsides, woodland margins. From Japan.


SYRINGA VILLOSA Vahl - . 2n = 46, 48.


Wooded bank. From China.


SYRINGA VULGARIS Linnaeus - Common Lilac. 2n = (38), 44, 46, (48).


Roadsides, woodland margins. From southeastern Europe.

Syringa hybrids

SYRINGA X CHINENSIS Willdenow (pro species) - .


[S. X PERSICA Linnaeus X S. VULGARIS Linnaeus]


SYRINGA X PERSICA Linnaeus (pro species) - .


[S. PROTOLACINIATA P.S. Green & M.C. Chang X S. VULGARIS Linnaeus]





Designed by Ray Angelo. Revised Jan. 19, 2017