1. Perennial erect herb with white flowers; circumboreal
   - northern Jacob's ladder

Type of: polemonium

Encyclopedia: Polemonium boreale

• genus Serratula
• genus Sertularia
• genus Sesamum
• genus Sesbania
• genus Seseli
• genus Setaria
• genus Setophaga
• genus Shigella
• genus Shorea
• genus Shortia
• genus Sialia
• genus Sialis
• 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