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
Sprenger or Emerald Asparagus
Squawbush, Skunkbush, Three Leaf Su
St. Catherine's Lace
Stella de Oro Daylily
Stellar Lights Bearded Iris