Sneezeweed, Fine-leaved, 483 
Purple-headed, 482 
White, 487 
Sneezewort, 481 
Snow-on-the-mountain, 267 
Soapwort, 149 
Solanum carolinense, 365 
Dulcamara, 363 
eleagnifolium, 367 
Solanum nigrum, 364 
rostratum, 368 
Solidago canadensis, 425 
graminifolia, 426 
mollis, 424 
nemoralis, 423 
rigida, 426 
Sonchus arvensis, 537 
asper, 539 
oleraceus, 5388 
Sorghum halepense, 22 
Sorrel, Field, 95 
Garden, 94 
Horse, 95 
Lady’s, 256 
Redtop, 95 
Sheep, 95, 255 
Tall, 94 
Sowbane, 114 
Sow Thistle, Common, 538 
Corn, 537 
Creeping, 537 
Field, 537 
Spiny-leaved, 539 
Spatling, 148 
Spearmint, 362 
Speckled John, 284 
Specularia perfoliata, 408 
Speedwell, Common, 383 
Corn, 386 
Field, 387 
Garden, 387 
Purslane, 385 
Thyme-leaved, 385 
Upland, 383 
Spergula arvensis, 136 
Spermacoce glabra, 399 
Spinach, Strawberry, 110 
Spirea latifolia, 203 
salicifolia, 204 
tomentosa, 204 
Sporobolus indicus, 47 
neglectus, 47 
INDEX 
Sporobolus vaginiflorus, 46 
Spurge, Creeping, 266 
Cypress, 272 
Flowering, 268 
Hairy, 265 
Leafy, 271 
Pasture, 264 
Spotted, 266 
Stubble, 264 
Sun, 272 
Thyme-leaved, 263 
Toothed, 269 
Upright Spotted, 264 
Various-leaved, 270 
White-margined, 267 
Spurry, 136 
Spurwort, 396 
Squirrel-tail, 64 
Stachys palustris, 357 
Stagger Bush, 310 
Stagger Weed, 162 
Staggerwort, 506 
Stammerwort, 455 
Star Thistle, Purple, 517 
Yellow, 518 
Starwort, 139 
Grassy, 138 
Yellow, 446 
Steeple-bush, 204 
Stellaria graminea, 138 
media, 139 
Stickseed, European, 334 
Large-flowered, 335 
Many-flowered, 336 
Purple-stemmed, 375 
Virginia, 334 
Western, 335 
Sticktight, 473 
Sticky-stem, 291 
Stinkweed, 488 
Stinking Willie, 506 
Stipa comata, 40 
spartea 39 
Stipa, Western, 40 
Stitchwort, Grass-leaved, 138 
Lesser, 138 
Stonecrop, Mossy, 200 
Stork’s-bill, 258 
Strophostyles helvola, 253 
paucifiora, 254 
umbellata, 254 
Succory, 525 
589 
