Dorotheanthus (ice plant) Dorstenia Doryanthes (spear lily) Doryopteris Draba Dracaena Dracocephalum Dracula (an orchid genus) Sorbaria Sorbus (rowan, whitebeam) Sorghastrum Sparaxis Sparganium [220px-Sparganium_simplex_hoffm] Simplestem bur-reed (Sparganium erectum ssp. stoloniferumà) Sparrmania Spartina (cord grass) Spartium (broom) Spathiphyllum Spathodea Sphaeralcea Spigelia Spiraea (spirea) Sprianthes (an orchid genus) Calytrix (starflower) Camassia (quamash) Camellia Campanula (bellflower) Campsis (trumpet vine) Campylotropsis Canarina Canistrum Canna Cantua Capsicum (pepper) Caragana (peashrub) Caralluma Cardamine (bittercress) Cardiocrinum Cardiospermum Carex (sedge) Carissa Carlina Carludovica Carmichaelia Carnegiea (saguaro) Carpentaria Carpenteria Carpinus (hornbeam) Carpobrotus Carthamus (safflower) Carum (caraway) Carya (hickory, pecan) Caryopteris Caryota (fishtail palm) Cassia Cassinia Cassiope Castanea (chestnut) Castanopsis Castanospermum Casuarina Catalpa Catananche Catasetum (an orchid genus) Caulophyllum Cautleya Cavendishia Ceanothus (California-lilac) Cedronella Cedrus (cedar) Ceiba (Kapok) Celastrus (staff-vine) Celmisia (New Zealand daisy) Celosia (cockscomb) Celtis (hackberry) Centaurea Centaurium Centradenia Centranthus (valerian) Cephalaria Cephalocereus Cephalophyllum Cephalotaxus (plum-yew) Ceraria Cerastium Ceratopetalum Ceratophyllum Ceratopteris Ceratostigma Ceratozamia Cercidiphyllum Cercis Cercocarpus Cereus Ceropegia Cestrum Chaenomeles (flowering quince) Chaenorhinum (dwarf snapdragon) Chaerophyllum Chamaecyparis (cypress) Chamaecytisus Chamaedaphne Chamaedorea Chamaelirium Chamaemelum (chamomile) Chamaerops Chamelaucium Chasmanthe Chasmanthium Cheilanthes