Bull. Torrey Bot. Club 20: 213, plate 156. 1893.
Herbs. Stems erect, green to brownish, simple or branched from base, not wiry, 4–50 cm, glabrous or papillose-scabrid-ulous. Leaves uniformly distributed, articulated to ocreae, basal leaves persistent or caducous, distal leaves abruptly or gradually reduced to bracts; ocrea 4–10 mm, glabrous or papillose-scabridulous, proximal part cylindric, distal part lacerate or disintegrating into a few persistent fibers; petiole 0.1–2 mm; blade 1-veined, not pleated, linear or narrowly oblong to oblanceolate, 8–45 × 2–8(–12) mm, margins revolute or flat, smooth or papillose-denticulate, apex acute, mucronate, rarely obtuse. Inflorescences axillary or axillary and terminal, spikelike, elongate; cymes widely spaced along branches, 2–4-flowered. Pedicels enclosed in or exserted from ocreae, erect, 1–4 mm. Flowers closed or at least some open; perianth (2.5–)4 mm; tube 20–40% of perianth length; tepals overlapping, greenish or reddish, sometimes flushed with purple, with white or pink margins, sepaloid or petaloid, oblong or oblong-elliptic, cucullate, navicular, apex rounded; midveins unbranched or with few branches at base; stamens 3–8. Achenes enclosed in perianth, black, elliptic or ovate, 2.5–3.3 mm, faces subequal, shiny, smooth.
Alta., B.C., Sask., Ariz., Calif., Colo., Idaho, Mont., N.Dak., N.Mex., Nebr., Nev., Oreg., S.Dak., Utah, Wash., Wyo.
Subspecies 2 (2 in the flora).
|1||Stems and ocreae glabrous; leaf blades linear-lanceolate to narrowly oblong or oblanceolate, margins smooth; flowers closed||Polygonum sawatchense subsp. sawatchense|
|1||Stems and ocreae papillose-scabridulous; leaf blades elliptic or oblong-elliptic, margins papillose-denticulate; at least some flowers open||Polygonum sawatchense subsp. oblivium|