1. Bog plant of pine barrens of southeastern United States having spikes of irregular yellow-orange flowers
   - yellow milkwort, candyweed, yellow bachelor's button, Polygala lutea

Type of: milkwort

• genus Sida
• genus Sidalcea
• genus Sideritis
• genus Sigmodon
• genus Silene
• genus Sillago
• genus Silphium
• genus Silurus
• genus Silvia
• genus Silybum
• genus Simarouba
• genus Simulium
• genus Sinanthropus
• genus Sinapis
• genus Sinningia
• genus Sinornis
• genus Siren
• genus Sison
• genus Sistrurus
• genus Sisymbrium
• genus Sisyrinchium
• genus Sitophylus
• genus Sitotroga
• genus Sitta
• genus Sium