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

California knotweed

Habit Herbs, compact, often cushion-like. Herbs.
Stems

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

erect, green, simple or divaricately branched, ± wiry, 4–40 cm, papillose-scabridulous.

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.

uniformly distributed, not articulated to ocreae, basal leaves usually caducous, distal leaves abruptly reduced to bracts;

ocrea 5–10 mm, glabrous or papillose-scabridulous, proximal part cylindric, distal part white or tawny, disintegrating into ± bristly-fringed fibers;

petiole absent;

blade 3-veined, without pleats, linear, 5–25(–30) × 0.5–2 mm, margins revolute, papillose-denticulate or smooth, apex mucronate or weakly spine-tipped.

Inflorescences

axillary;

cymes in most axils, 1-flowered.

axillary;

cymes in distal axils, 1-flowered.

Pedicels

absent.

absent.

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.

open or closed;

perianth 2.5–3.5 mm;

tube 10–20% of perianth length;

tepals overlapping, uniformly white to pink, petaloid, elliptic, navicular, apex acute to acuminate;

midveins unbranched;

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, brown, narrowly elliptic, 1.8–2.2 mm, faces subequal, shiny, smooth.

Polygonum parryi

Polygonum californicum

Phenology Flowering May–July. Flowering May–Sep.
Habitat Vernally moist, open, sandy or rocky places Open places, including serpentine
Elevation 500-2000 m (1600-6600 ft) 40-1200 m (100-3900 ft)
Distribution
from FNA
CA; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 5, p. 563. FNA vol. 5, p. 564.
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. 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. parryi, P. patulum, P. plebeium, P. polygaloides, P. ramosissimum, P. sawatchense, P. shastense, P. spergulariiforme, P. striatulum, P. tenue, P. utahense
Synonyms Duravia californica, P. greenei
Name authority Greene: Bull. Torrey Bot. Club 8: 99. (1881) Meisner: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 14: 100. (1856)
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