Polygonum cascadense

W. H. Baker

Madroño 10: 62, plate 1, fig. 1. 1949.

Common names: Cascade knotweed
Endemic
Treatment appears in FNA Volume 5. Treatment on page 571. Mentioned on page 561, 562.
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Herbs. Stems spreading to erect, zigzagged, green, simple or branched from base, wiry, 5–12(–15) cm, glabrous. Leaves uniformly distributed, articulated to ocreae, basal leaves persistent, distal leaves abruptly reduced to bracts; ocrea 2–5 mm, glabrous, proximal part funnelform, distal part lacerate; petiole essentially absent; blade 1-veined, not pleated, oblanceolate to obovate, 5–20 × 2–5 mm, margins revolute, never touching along midrib, sparsely papillose-denticulate, apex rounded or apiculate. Inflorescences axillary and terminal, spikelike, dense; cymes congested at tips of stems and branches, 3–5-flowered. Pedicels enclosed in ocreae, erect to spreading, 2–3 mm. Flowers open; perianth 2–2.5 mm; tube 12–25% of perianth length; tepals overlapping, uniformly white, petaloid, oblong to obovate, cucullate, navicular in distal 1/4, apex rounded; midveins unbranched; stamens 8. Achenes enclosed in or exserted from perianth, black, ovate to ovate-oblong, 1.8–2.1 mm, faces subequal, shiny, smooth.


Phenology: Flowering Jun–Sep.
Habitat: Dry, usually rocky slopes, often on serpentine
Elevation: 1600-1800 m

Discussion

Selected References

None.

Lower Taxa

None.
... more about "Polygonum cascadense"
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
W. H. Baker +
Cascade knotweed +
1600-1800 m +
Dry, usually rocky slopes, often on serpentine +
Flowering Jun–Sep. +
Undefined sect. Duravia +  and Polygonum sect. Monticola +
Polygonum cascadense +
Polygonum sect. Duravia +
species +