Kellogg's knotweed

Polygonum kelloggii Greene, Fl. Francisc., 134. 1891; P. minutissimum L. O. Williams; P. unifolium Small ex Rydberg

Stems 2-15 cm. Inflorescences mostly terminal, prolonged almost to base of stems, ovoid, 3-15 × 5-15 mm, or ± continuous; bracts ± patent, linear to linear-lanceolate, 7-25 mm, soft, margins flat or revolute, green, not scarious; lateral and midveins inconspicuous. Flowers: perianth 1.5-2.3 mm; tube 19-34% of perianth length; tepals pink or white; perianth tube and base of tepals smooth; stamens 3. Achenes light yellow to greenish brown, ovate, 1.3-1.7 mm, smooth to obscurely longitudinally reticulate, shiny.

Flowering Jun-Sep. Mountain meadows, seeps, vernal pools, dry subalpine slopes; 1300-3300 m; B.C.; Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, Wash., Wyo.