Silver Maple
Silverberry, Thorny Elaeagnus
Small Flower Tamarisk
Small Soapweed
Smoketree, Wigtree
Smooth Agave
Snow-In-Summer
Soaptree Yucca
Society Garlic
Sonoran tree bear grass
Southern Sword Fern
Southwestern Cosmos
Spanish Lavender
Spartan Columnar Juniper
Spider Agave
Spike Gayfeather
Spike Lavender
Spineless Yucca
Spotted Emu Bush
Spreading Germander