Polygonum davisiae

Davis' Knotweed

Stems in clump or single, decumbent to upright. Leaves sessile or with short petiole. Leaf yellow-green, often coated with white waxy powder, lance-shaped to round, less than 2 in. long. Flowers in small clusters of 2–5 at leaf axils. Petals yellow, green, or purple. Grows in rocky sites or talus above treeline. Similar P. newberryi, with 5–25 flowers in cluster, grows in pumice in alpine areas, including Crater Lake, Mount Shasta, and Mount Rainier in Cascades of Oregon and Washington.

  • Rarity: Locally Common
  • Flowering Time: All Summer
  • Life Cycle: Perennial
  • Height: under 16 inches
  • Habitat: Alpine, Subalpine
  • Found In: Siskiyous
  • Native: Yes