1. Perennial of western North America having white flowers
   - white prairie aster

Type of: aster

• family Otididae
• family Oxalidaceae
• family Oxyuridae
• family Paeoniaceae
• family Paguridae
• family Palaemonidae
• family Palinuridae
• family Palmaceae
• family Palmae
• family Pandanaceae
• family Pandionidae
• family Panorpidae
• family Papaveraceae
• family Papilionacea
• family Paradisaeidae
• family Paridae
• family Parkeriaceae
• family Parmeliaceae
• family Parulidae
• family Passeridae
• family Passifloraceae
• family Patellidae
• family Pectinidae
• family Pedaliaceae
• family Pediculidae