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

broad-leaf knotweed, broad-leaf or leafy dwarf knotweed, leafy dwarf knotweed, little mountain knotweed, zigzag knotweed

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

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

prostrate to erect, often zigzagged, reddish brown, simple or branched from base, wiry, 2–30 cm, papillose-scabrid-ulous.

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.

evenly distributed or crowded at branch tips, articulated to ocreae, basal leaves persistent, hardly reduced distally;

ocrea 1–4 mm, papillose-scabridulous, proximal part cylindric, distal part entire or dentate-lacerate;

petiole 0.1–3 mm;

blade 1-veined, not pleated, narrowly elliptic, elliptic, ovate, obovate, or subround, 6–27 × 3–8 mm, margins flat, smooth, irregularly thickened or papillose-denticulate, apex apiculate, green adaxially.

Inflorescences

axillary;

cymes in most axils, 1-flowered.

axillary;

cymes from near stem and branch bases, sometimes also crowded at branch apices, 1–3-flowered.

Pedicels

absent.

enclosed in ocreae, erect to spreading, 2–3 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 closed;

perianth 1.8–2.5 mm;

tube 22–29% of perianth length;

tepals overlapping, greenish with narrow white or pink margins, almost sepaloid, oblong, cucullate, ± navicular, apex rounded;

midveins thickened, 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 perianth or tip exserted, black, elliptic to ovate, 1.8–2.3 mm, faces subequal, smooth, shiny.

Polygonum parryi

Polygonum minimum

Phenology Flowering May–July. Flowering Jul–Sep.
Habitat Vernally moist, open, sandy or rocky places Alpine to subalpine sites, open or semibarren soil
Elevation 500-2000 m (1600-6600 ft) 1500-3300 m (4900-10800 ft)
Distribution
from FNA
CA; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 5, p. 563. FNA vol. 5, p. 569.
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. 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 P. torreyi
Name authority Greene: Bull. Torrey Bot. Club 8: 99. (1881) S. Watson: Botany (Fortieth Parallel), 315. (1871)
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