Bolander's knotweed

Duravia bolanderi (W. H. Brewer) Greene

Shrubs. Stems erect, brown, simple, wiry, gnarled with age, 20-60 cm, glabrous. Leaves crowded at branch tips, not articulated to ocreae, basal leaves caducous or persistent, distal leaves abruptly reduced to bracts; ocrea 6-10 mm, glabrous or papillose-scabridulous, proximal part cylindric, distal part silvery, deeply fringed, disintegrating; petiole absent; blade 3-veined, without pleats, linear to subulate, 3-15(-25) × 0.4-1.5 mm, margins flat, smooth, apex acuminate to spine-tipped. Inflorescences axillary; cymes in distal axils, 1-2-flowered. Pedicels absent. Flowers semi-open; perianth 2.6-3.2 mm; tube 18-33% of perianth length; tepals overlapping, ± recurved, uniformly white to pink, petaloid, elliptic-oblong to obovate, navicular, apex rounded; midveins unbranched; stamens 8. Achenes enclosed in perianth, light brown, lanceolate to oblong-ovate, 2.5-3 mm, faces subequal, shiny, smooth.

Flowering Jun-Nov. Open, dry, gravelly, rocky places; 300-1500 m; Calif.

Polygonum bolanderi is known from several counties in northwestern California (Butte, Napa, Shasta, and Sonoma).