Sawatch Knotweed Flower Sawatch Knotweed Stem Sawatch Knotweed Plant

Wildflowers of Southern Arizona


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Sawatch Knotweed.
Polygonum sawatchense.
Buckwheat (Polygonaceae) family.

Herbs. Stems erect, green to brownish, simple or branched from base, not wiry, 4-50 cm, glabrous or papillose-scabridulous. 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.

Santa Catalina Mountains.
Location: Oracle Ridge Trail.
7/30/15

See SEINet Pictures and Description

Thumb: Prostrate Knotweed
« P. Knotweed
Thumb: Flattoped Buckwheat
F. Buckwheat »