Broadleaf Knotweed

Herbs. Stems prostrate to erect, often zigzagged, reddish brown, simple or branched from base, wiry, 2-30 cm, papillose-scabrid-ulous. Leaves evenly distributed or crowded at branch tips, arti-culated to ocreae, basal leaves persistent, hardly reduced distally; ocrea 1-4 mm, papillose-scabridulous, proximal part cylindric, distal part entire or dentate-lacerate; petiole 0.1-3 mm; blade 1-veined, not pleated, narrowly elliptic, elliptic, ovate, obovate, or subround, 6-27 × 3-8 mm, margins flat, smooth, irregularly thickened or papillose-denticulate, apex apiculate, green adaxially. Inflorescences axillary; cymes from near stem and branch bases, sometimes also crowded at branch apices, 1-3-flowered. Pedicels enclosed in ocreae, erect to spreading, 2-3 mm. Flowers semi-open or closed; perianth 1.8-2.5 mm; tube 22-29% of perianth length; tepals overlapping, greenish with narrow white or pink margins, almost sepaloid, oblong, cucullate, ± navicular, apex rounded; midveins thickened, unbranched; stamens 8. Achenes enclosed in perianth or tip exserted, black, elliptic to ovate, 1.8-2.3 mm, faces subequal, smooth, shiny.

Alta., B.C.; Alaska, Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.

Flowering Jul-Sep.

Alpine to subalpine sites, open or semibarren soil; 1500-3300m.

Polygonum torreyi S. Watson

Polygonum minimum is a species of flowering plant in the knotweed family known by the common name broadleaf knotweed. It is native to much of western North America where it can be found in mountainous regions. It grows in the subalpine and alpine climates of high mountain ranges from Alaska to Arizona and New Mexico.