Stems green to brownish, usually branched from base, 4-50 cm, glabrous. Leaves basal leaves caducous or persistent, distal leaves abruptly reduced to bracts, rarely much longer than flowers; ocrea glabrous; blade linear-lanceolate to narrowly oblong or oblanceolate, 15-45 × 2-8(-12) mm, margins usually revolute, smooth. Inflorescences axillary or axillary and terminal, long, open, racemes, 5-15 cm; cymes (1-)2-4-flowered. Pedicels 1-4 mm. Flowers closed; perianth (2.5-)3-3.5 mm; tube 25-40% of perianth length; tepals greenish or reddish with white or pink margins, oblong; midveins greenish or brown, unbranched or with few branches at base; stamens 3-8. Achenes ovate or elliptic, 2.5-3 mm. Flowering Jun-Aug. Dry meadows, pastures, sagebrush and forests on sandy, gravelly, or rocky substrates; 800-3500 m; Alta., Sask.; Ariz., Calif., Colo., Idaho, Mont., Nebr., Nev., N.Mex., N.Dak., S.Dak., Utah, Wash., Wyo.
Kearney and peebles 1969, McDougall 1973
Duration: Annual Nativity: Native Lifeform: Forb/Herb General: Herbaceous annual, stems slender, simple or branching from the base, jointed, often swollen at the nodes, stems to 30 cm tall. Leaves: Alternate, oblanceolate to obovate or linear, margins entire, the upper leaves reduced to subulate bracts, the stipules united in a sheath, the sheath often fringed. Flowers: No corolla, the calyx small, green or whitish on the margins, mostly perfect, the perianth cleft or parted, with 4-5 lobes, borne in clusters of 2-3 in the leaf axils, the pedicels jointed, stamens 5-9, stigmas 2-3. Fruits: Achenes which are shiny, black, smooth, and sharply 3-angled. Ecology: Found in dry pine woods, from 5,500-9,000 ft (1676-2743 m); flowering June-September. Notes: The keys to this species are the slender stems, the upper leaves reduced to subulate bracts, and the shiny, black, smooth achenes with acute angles. Ethnobotany: Unknown Etymology: Polygonum is derived from Greek polys, many, and gonu, knee or goint, while swatchense is named for the Sawatch Mountains in Colorado. Synonyms: Polygonum douglasii subsp. johnstonii, Polygonum douglasii var. johnstonii, Polygonum exile, Polygonum triandrum, Polygonum douglasii var. johnstonii, Polygonum sawatchense, Polygonum triandrum, Polygonum utahense Editor: LCrumbacher, 2011