Polygonum sawatchense
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.
Distribution
w North America.
Discussion
Subspecies 2 (2 in the flora).
Selected References
None.
Key
| 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 |