| Family |
Taxon |
Common Name | Photographs |
| Asteraceae |
Rudbeckia laciniata L. |
cut-leaved coneflower, wild golden-glow |
|
| Asteraceae |
Rudbeckia laciniata L. var. laciniata |
cut-leaved coneflower, wild golden-glow |
|
| Polygonaceae |
Rumex acetosella L. |
common sheep sorrel, field sorrel, red sorrel, sheep sorrel |
|
| Polygonaceae |
Rumex britannica L. |
great water dock |
|
| Polygonaceae |
Rumex verticillatus L. |
swamp dock, water dock |
|
| Alismataceae |
Sagittaria latifolia Willd. |
broad-leaved arrow-head, common arrow-head, duck-potato, wapato |
|
| Salicaceae |
Salix bebbiana Sarg. |
beaked willow, Bebb's willow |
|
| Chenopodiaceae |
Salsola tragus L. |
prickly Russian thistle, Russian thistle, tumbleweed |
|
| Caprifoliaceae |
Sambucus racemosa L. subsp. pubens (Michx.) House var. pubens (Michx.) Koehne |
red elderberry, red-berried elder, scarlet elderberry |
|
| Papaveraceae |
Sanguinaria canadensis L. |
bloodroot |
|
| Apiaceae |
Sanicula marilandica L. |
black snakeroot, Maryland sanicle |
|
| Sarraceniaceae |
Sarracenia purpurea L. subsp. purpurea |
purple pitcher-plant |
|
| Poaceae |
Schizachne purpurascens (Torr.) Swallen |
false melic grass |
|
| Cyperaceae |
Scirpus atrovirens Willd. |
black bulrush, dark-green bulrush |
|
| Cyperaceae |
Scirpus cyperinus (L.) Kunth |
wool-grass |
|
| Cyperaceae |
Scirpus microcarpus J.Presl & C.Presl |
panicled bulrush |
|
| Selaginellaceae |
Selaginella eclipes W.R.Buck |
hidden spike-moss, northern meadow spike-moss |
|
| Selaginellaceae |
Selaginella rupestris (L.) Spring |
dwarf spike-moss, northern selaginella, rock spike-moss |
|
| Brassicaceae |
Sisymbrium altissimum L. |
tall tumble mustard |
|
| Iridaceae |
Sisyrinchium montanum Greene |
mountain blue-eyed-grass, strict blue-eyed grass |
|
| Apiaceae |
Sium suave Walter |
hemlock water-parsnip, water-parsnip |
|
| Smilacaceae |
Smilax illinoensis Mangaly |
Illinois carrion-flower, Illinois greenbrier |
|
| Solanaceae |
Solanum dulcamara L. |
bittersweet nightshade, climbing nightshade, deadly nightshade |
|
| Solanaceae |
Solanum ptychanthum Dunal |
eastern black nightshade, West Indian nightshade |
|
| Asteraceae |
Solidago canadensis L. |
Canadian goldenrod, common goldenrod |
|
| Asteraceae |
Solidago canadensis L. var. hargeri Fernald |
Canadian goldenrod, Harger's goldenrod |
|
| Asteraceae |
Solidago gigantea Aiton |
giant goldenrod, late goldenrod, smooth goldenrod |
|
| Asteraceae |
Solidago nemoralis Aiton |
dyer's-weed goldenrod, gray goldenrod, old-field goldenrod |
|
| Asteraceae |
Solidago patula Muhl. ex Willd. var. patula |
rough-leaved goldenrod, round-leaved goldenrod, swamp goldenrod |
|
| Asteraceae |
Sonchus arvensis L. |
field sow-thistle, perennial sow-thistle |
|
| Asteraceae |
Sonchus arvensis L. var. glabrescens Günther, Grab. & Wimm. |
marsh sow-thistle |
|
| Poaceae |
Sphenopholis intermedia (Rydb.) Rydb. |
slender wedge grass |
|
| Orchidaceae |
Spiranthes casei Catling & Cruise var. casei |
Case's lady's-tresses |
|
| Orchidaceae |
Spiranthes cernua (L.) Rich. |
nodding lady's-tresses |
|
| Orchidaceae |
Spiranthes lacera (Raf.) Raf. |
northern slender lady's-tresses |
|
| Orchidaceae |
Spiranthes lacera (Raf.) Raf. var. lacera |
northern slender lady's-tresses |
|
| Poaceae |
Sporobolus vaginiflorus (Torr. ex A.Gray) A.W.Wood var. vaginiflorus |
poverty grass, poverty drop-seed, sheathed drop-seed |
|
| Staphyleaceae |
Staphylea trifolia L. |
American bladdernut |
|
| Liliaceae |
Streptopus lanceolatus (Aiton) Reveal var. longipes (Fernald) Reveal |
twisted-stalk |
|
| Potamogetonaceae |
Stuckenia pectinata (L.) Börner |
comb pondweed, sago pondweed |
|
| Araceae |
Symplocarpus foetidus (L.) Salisb. ex W.P.C.Barton |
skunk-cabbage |
|
| Asteraceae |
Taraxacum officinale Weber |
common dandelion |
|
| Ranunculaceae |
Thalictrum dioicum L. |
early meadow-rue, quicksilver-weed |
|
| Brassicaceae |
Thlaspi arvense L. |
field pennycress |
|
| Cupressaceae |
Thuja occidentalis L. |
eastern arborvitae, northern white-cedar |
|
| Anacardiaceae |
Toxicodendron rydbergii (Small ex Rydb.) Greene |
Rydberg's poison-ivy, western poison-ivy |
|
| Primulaceae |
Trientalis borealis Raf. subsp. borealis |
American starflower |
|
| Fabaceae |
Trifolium aureum Pollich |
golden clover, palmate hop clover, yellow hop clover |
|
| Fabaceae |
Trifolium repens L. |
white clover |
|
| Juncaginaceae |
Triglochin maritima L. |
arrow-grass, common bog arrow-grass, seaside arrow-grass |
|