Polygala knotweed

Herbs. Stems erect, green, usually divaricately branched, rarely simple, ± wiry, (2-)6-20(-25) cm, glabrous. Leaves uniformly dis-tributed, articulated to ocreae, basal leaves often caducous, distal leaves abruptly reduced to bracts; ocrea 4-8 mm, glabrous, prox-imal part cylindric, distal part silvery, with inconspicuous veins, lacerate; petiole absent; blade 3-veined, lateral veins sometimes inconspicuous, without pleats, narrowly linear, 10-40 × 1-2.5 mm, margins ± revolute, smooth, apex acute or mucronate. Inflorescences axillary and terminal, spikelike, subglobose to cylindric; cymes in most axils or crowded distally, 1-3-flowered. Pedicels enclosed in ocreae, erect, 0.1-2 mm, sometimes absent. Flowers mostly closed; perianth 1.5-3 mm; tube 19-40% of perianth length; tepals overlapping, uniformly white, pink, or red, petaloid, oblong-lanceolate, ± navicular, apex acute to acuminate; midveins usually unbranched or with 2 lateral branches proximally, moderately to strongly thickened, tepals appearing ± keeled; stamens 3-8. Achenes enclosed in perianth, light yellow, light brown, or greenish brown to dark brown, ovate to lanceolate, 1.3-2.5 mm, faces subequal, shiny or dull, smooth or reticulate with longitudinal ridges.

Subspecies 4 (4 in the flora): w North America.

J. C. Hickman's (1993c) treatment of the Polygonum polygaloides complex is provisionally accepted here. Most of the intermediate specimens occur between subspp. confertiflorum, esotericum, and kelloggii. Alternatively, P. polygaloides could be recognized in the narrow sense and the three other taxa could be treated as subspecies of a separate P. kelloggii, the earliest available binomial.