Sanicle _Sanicula_ 52 Sassafras _Sassafras_ 59 Scouringrush _Equisetum_ 28 Scurfpea _Psoralea_ 33 Seablite _Suaeda_ 54 Sedge _Carex_ 27 Seedbox _Ludwigia_ 47 Seepweed _Suaeda_ 54 Selenia _Selenia_ 52 Selfheal _Prunella_ 51 Senna _Cassia_ 31 Sensitivebriar _Schrankia_ 34 Sensitivefern _Onoclea_ 28 Serradella _Ornithopus_ 33 Serviceberry _Amelanchier_ 55 Sesame _Sesamum_ 52 Sesbania _Sesbania_ 34 Shepherdspurse _Capsella_ 38 Shootingstar _Dodecatheon_ 41 Sicklepod _Arabis canadensis_ 36 Sida _Sida_ 52 Silene _Silene_ 52 Silvergrass _Miscanthus_ 22 Sisymbrium _Sisymbrium_ 53 Skeletongrass _Gymnopogon_ 22 Skeletonplant _Lygodesmia_ 47 Skullcap _Scutellaria_ 52 Sleepygrass _Stipa robusta_ 26 Sloughgrass _Beckmannia_ 19 Smartweed _Polygonum_ 50 Smilograss _Oryzopsis miliacea_ 23 Smutgrass, rattail _Sporobolus poiretii_ 26 Snailseed _Cocculus_ 39 Snakecotton _Froelichia_ 43 Snakeroot, white _Eupatorium rugosum_ 42 Snakeweed _Gutierrezia_ 43, 57 Snapweed _Impatiens_ 45 Sneezeweed _Helenium_ 44 Snowberry _Symphoricarpos_ 59 Snow-on-the-mountain _Euphorbia marginata_ 42 Soapberry _Sapindus_ 59 Soapweed _Yucca_ 30, 59