Polygonum heterosepalum

M. Peck & Ownbey

Madroño 10: 250. 1950.

Common names: Dwarf desert knotweed
EndemicConservation concern
Treatment appears in FNA Volume 5. Treatment on page 563. Mentioned on page 548, 561, 562.

Herbs, compact, often cushion-like. Stems erect, green or reddish, simple or branched near base, not wiry, 1.5–5 cm, glabrous. Leaves uniformly distributed, dense, not articulated to ocreae, basal leaves persistent or caducous, distal leaves gradually reduced to bracts; ocrea 3–6 mm, glabrous, proximal part cylindric, distal part disintegrating almost to base, with whitish, straight, rigid fibers; petiole absent; blade 3-veined, without pleats, linear to lanceolate, 10–20 × 0.6–2.7 mm, margins revolute, smooth, apex spine-tipped. Inflorescences axillary; cymes in most axils, 2–3-flowered. Pedicels enclosed in ocreae, erect, 0.1–1 mm. Flowers closed; perianth 2.3–2.7 mm; tube 3–7% of perianth length; tepals overlapping, whitish with whitish or pink margins, petaloid, oblong, navicular, dimorphic, outer 2 shorter than inner 3, outer 2 0.8–1.2 mm, inner 2.3–2.7 mm, papillose at base, apex acute or acuminate; midveins unbranched; stamens 5–6. Achenes enclosed in perianth, olive brown, narrowly ovate to ovate-lanceolate, 1.5–2 mm, faces subequal, shiny, smooth.


Phenology: Flowering Jun–Aug.
Habitat: Dry waste ground, open flats in sagebrush plains, ponderosa pine forests
Elevation: 1000-1500 m

Discussion

Of conservation concern.

Selected References

None.

Lower Taxa

None.
... more about "Polygonum heterosepalum"
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
M. Peck & Ownbey +
Dwarf desert knotweed +
Idaho +, Nev. +  and Oreg. +
1000-1500 m +
Dry waste ground, open flats in sagebrush plains, ponderosa pine forests +
Flowering Jun–Aug. +
Endemic +  and Conservation concern +
Undefined sect. Duravia +  and Polygonum sect. Monticola +
Polygonum heterosepalum +
Polygonum sect. Duravia +
species +