Sideritis Silene (campion) Silphium Silybum Simmondsia (jojoba) Sinningia Sinofranchetia Sinojackia Sinowilsonia Sisyrinchium Skimmia Smilacina Smilax Smithiantha Smyrnium Sobralia an orchid genus Solandra Solanum (potato, nightshade) Soldanella (snowbell) Soleirolia Solenopsis Solenostemon Solidago (goldenrod) Solidaster (supposedly hybrid genus; see Solidago) Sollya Sonerila Sophora × Sophrolaeliocattleya (trigeneric hybrid orchid) Sophronitis (an orchid genus) Sorbaria Sorbus (rowan, whitebeam) Sorghastrum Sparaxis Sparganium (bur-reed) Sparrmannia Spartina (cord grass) Spartium (broom) Spathiphyllum Spathodea Sphaeralcea Spigelia Spiraea (spirea) Sprianthes (an orchid genus) Sporobolus Sprekelia Stachys (betony) Stachyurus Stangeria Stanhopea (an orchid genus) Stapelia Stapelianthus Staphylea (bladdernut) Stauntonia Stenanthium Stenocactus Stenocarpus Stenocereus Stenomesson Stenotaphrum Stenotus Stephanandra Stephanocereus Stephanotis Sternbergia Stigmaphyllon Stipa Stokesia Stomatium Stratiotes Strelitzia (bird of paradise) Streptocarpus (Cape primrose) Streptosolen Strobilanthes Stromanthe Strombocactus Strongylodon Stuartia Stylidium Stylophorum Styphelia Styrax Succisa Sulcorebutia Sutera Sutherlandia Swainsona Swainsonia Syagrus Sycoparrotia (hybrid genus) Sycopsis Symphoricarpos (snowberry) Symphyandra Symphytum (comfrey) Symplocos Synadenium Syneilesis Syngonium Synthyris Syringa (lilac) Syzygium (rose apple) T Tabebuia Tabernaemontana Tacca Tagetes (Mexican or French marigold) Talinum (fameflower) Tamarix (tamarisk) Tanacetum (tansy) Tanakaea Tapeinochilos Taxodium (bald cypress) Taxus (yew) Tecoma Tecomanthe Tecomaria Tecophilaea Telekia Telephium Tellima Telopea (waratah) Templetonia Terminalia Ternstroemia Tetracentron Tetradium (bee tree) Tetranema Tetraneuris Tetrapanax Tetrastigma Tetratheca Teucrium Thalia Thalictrum Thelesperma Thelocactus Thelypteris Thermopsis Thespesia Thevetia Thlaspi Thrinax (thatch palm) Thryptomene (heath myrtle) Thuja (thuja, arborvitae) Thujopsis (hiba) Thunbergia Thymophylla Thymus (thyme) Tiarella Tibouchina Tigridia Tilia (linden) Tillandsia (air plant, Spanish moss) Tipuana Titanopsis Tithonia (Mexican sunflower) Todea Tolmiea Tolpis Toona Torenia Torreya (nutmeg yew) Tovara Townsendia Trachelium Trachelium caeruleum (blue throatwort) Trachelospermum Trachycarpus (chusan palm) Trachymene Tradescantia (spiderwort) Trapa (water caltrop) Trichodiadema Trichosanthes Tricyrtis (toad lily) Trientalis Trifolium (clover) Trillium Tripetaleia Tripterygium Triteleia (triplet lily) Tritonia Trochodendron Trollius (globeflower) Tropaeolum (nasturtium) Tsuga (hemlock) Tsusiophyllum Tuberaria Tulbaghia Tulipa (tulip) Tweedia Tylecodon Typha (cattail) U Uebelmannia Ugni Ulex (gorse) Ulmus (elm) Umbellularia Uncinia Uniola Urceolina Urginea Ursinia Utricularia (bladderwort) Uvularia (merrybells, bellwort) V Valeriana (garden valerian) Vallea Vancouveria Vanda (an orchid genus) Vanilla an orchid genus Veitchia Vellozia Veltheimia Veratrum Verbascum (mullein) Verbena Vernonia (ironweed) Veronica (speedwell) Veronicastrum Verticordia Vestia Viburnum Victoria (giant waterlily) Vigna (cowpea and various beans) Viguiera Vinca (periwinkle) Viola (pansy, violet) Virgilia Viscaria Vitaliana Vitex Vitis (grape) Vriesea W Wachendorfia Wahlenbergia Waldsteinia Washingtonia Watsonia Weberocereus Wedelia Weigela Weingartia Weldenia Welwitschia Westringia Widdringtonia Wigandia Wigginsia Wikstroemia Wilsonaria (hybrid orchid genus) Wisteria Wittrockia Wolffia Woodsia Woodwardia (chain fern) Worsleya Wulfenia X Xanthoceras Xanthorhiza Xanthosoma Xeranthemum Xerophyllum Xylosma Y Yucca Yushania Z Zaluzianskya Zamia Zamioculcas Zantedeschia