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Parry's knotweed, Parry's or prickly knotweed, prickly knotweed

beach knotweed, beach or black or dune knotweed, black knotweed, dune knotweed

Habit Herbs, compact, often cushion-like. Shrubs or subshrubs.
Stems

erect, green-brown, simple or branched from base, not wiry, 2–5(–8) cm, glabrous.

prostrate or ascending, brown, branched, rooting at nodes, not wiry, 10–100 cm, glabrous, covered with remains of lacerate, hyaline ocreae.

Leaves

± uniformly distributed, dense, not articulated to ocreae, basal leaves ± persistent, distal leaves gradually reduced to bracts;

ocrea 2–4(–5) mm, glabrous, proximal part cylindric, distal part deeply lacerate, disintegrating into white, curled fibers;

petiole absent;

blade 3-veined, without pleats, linear-lanceolate, subulate, 5–13(–20) × 0.4–1 mm, margins revolute, smooth, apex spine-tipped.

crowded at branch tips, articulated to ocreae, basal leaves caducous or persistent, distal leaves not reduced in size;

ocrea 15–20 mm, glabrous, proximal part cylindric to funnelform, distal part silvery, entire or slightly lacerate, disintegrating into persistent white-gray curly fibers;

petiole 0–0.5 mm;

blade 1-veined, without pleats, linear to oblanceolate, (5–)10–20(–33) × 3–8 mm, coriaceous, margins revolute, smooth, apex acute or mucronate.

Inflorescences

axillary;

cymes in most axils, 1-flowered.

axillary;

cymes crowded in distal axils, 2–5-flowered.

Pedicels

absent.

enclosed in ocreae, erect to spreading, 2–5 mm.

Flowers

closed;

perianth 1.5–2(–2.5) mm;

tube 6–15% of perianth length;

tepals overlapping, usually reddish with white margins, petaloid, oblong, navicular, apex acute;

midveins unbranched;

stamens 8.

semi-open or open;

perianth (4.5–)6–10 mm;

tube 22–48% of perianth length;

tepals partially overlapping, uniformly pink or white, reddish brown when dried, petaloid, oblong-ovate to ± lanceolate, apex rounded;

midveins pinnately branched;

stamens 8.

Achenes

slightly exserted from perianth at maturity, dark brown, ovate, 1.2–1.6(–2) mm, faces subequal, shiny, smooth.

enclosed in or slightly exserted from perianth, black, ovate, 4–5 mm, faces subequal, shiny, smooth.

Polygonum parryi

Polygonum paronychia

Phenology Flowering May–July. Flowering Mar–Sep.
Habitat Vernally moist, open, sandy or rocky places Coastal sands, scrub along coast
Elevation 500-2000 m (1600-6600 ft) 0-50 m (0-200 ft)
Distribution
from FNA
CA; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; OR; WA; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Polygonum paronychia may be cultivated in rock gardens in open sites with sandy soil.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 5, p. 563. FNA vol. 5, p. 562.
Parent taxa Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Duravia Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Duravia
Sibling taxa
P. achoreum, P. argyrocoleon, P. austiniae, P. aviculare, P. bidwelliae, P. bolanderi, P. californicum, P. cascadense, P. douglasii, P. engelmannii, P. erectum, P. fowleri, P. glaucum, P. heterosepalum, P. hickmanii, P. humifusum, P. majus, P. marinense, P. minimum, P. nuttallii, P. oxyspermum, P. paronychia, P. patulum, P. plebeium, P. polygaloides, P. ramosissimum, P. sawatchense, P. shastense, P. spergulariiforme, P. striatulum, P. tenue, P. utahense
P. achoreum, P. argyrocoleon, P. austiniae, P. aviculare, P. bidwelliae, P. bolanderi, P. californicum, P. cascadense, P. douglasii, P. engelmannii, P. erectum, P. fowleri, P. glaucum, P. heterosepalum, P. hickmanii, P. humifusum, P. majus, P. marinense, P. minimum, P. nuttallii, P. oxyspermum, P. parryi, P. patulum, P. plebeium, P. polygaloides, P. ramosissimum, P. sawatchense, P. shastense, P. spergulariiforme, P. striatulum, P. tenue, P. utahense
Name authority Greene: Bull. Torrey Bot. Club 8: 99. (1881) Chamisso & Schlechtendal: Linnaea 3: 51. (1828)
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