TREATMENT FROM THE JEPSON MANUAL	previous taxon | next taxon Jepson Interchange (more information)
	©Copyright 1993 by the Regents of the University of California Print edition is available from the University of California Press

	The second edition of The Jepson Manual (2012) is available from the University of California Press
	See also the Jepson eFlora, which parallels the Second Edition

POLYGONACEAE

BUCKWHEAT FAMILY

James C. Hickman

Annual to trees, some dioecious
Stem: nodes often swollen
Leaves simple, basal or cauline, alternate, opposite, or whorled, generally entire; stipules 0 or obvious and fused into a generally scarious sheath around stem
Inflorescence: small cluster, axillary or arrayed in cymes or panicles; involucres sometimes subtending 1–many flowers
Flower generally bisexual, small, ± radial; perianth generally 5–6-lobed, base ± tapered, often jointed to pedicel; stamens 2–9, often in 2 whorls; ovary superior, styles generally 3, generally fused at base
Fruit: achene, generally enclosed by persistent perianth, generally 3-angled, ovoid, and glabrous
Genera in family: 50 genera, 1100 species: worldwide, especially n temp; some cultivated for food (Fagopyrum ; Rheum , rhubarb; Rumex , sorrel) or ornamental (Antigonon , coral-vine; Muehlenbeckia ; Polygonum )
Reference: [Ronse Decraene & Akeroyd 1988 Bot J Linn Soc 98:321–371; Reveal et al. 1989 Phytologia 66(2–4):83–414]
Treatments of the 15 eriogonoid genera are based on the monographic work of James L. Reveal, who is gratefully acknowledged.

POLYGONUM

KNOTWEED, SMARTWEED

Annual, perennial herb, shrub, vine
Stem prostrate to erect, or climbing, or floating, < 3 m
Leaves generally cauline, alternate, sessile or petioled; stipules fused, sheathing stem above nodes, generally scarious or membranous; blade sometimes obviously jointed to stipule sheath
Inflorescence: unit a 1–8-flowered cluster, these arrayed singly or in head-like to open panicles
Flower: perianth lobes generally 5; stamens 3–8, filaments generally wider at base
Fruit generally ovoid, 3-angled, sometimes round, flat, indented; shiny to dull, brown to black
Species in genus: ± 300 species: worldwide, especially n temp
Etymology: (Greek: many knees, from swollen nodes of some species)
Reference: [Ronse Decraene & Ackeroyd 1988 Bot J Linn Soc 98:321–371]
Segregate genera (e.g., Bistorta, Fallopia, Persicaria ) are sometimes recognized.

Native

P. polygaloides Meisn.

Annual
Stem 1–30 cm, slender, ± angled; ribs 0 or obscure
Leaves < 4 cm, sessile, joint with stipule obvious; lower blades linear to narrowly lanceolate
Inflorescence 1–7 cm, ± crowded at stem tips; bracts narrowly lanceolate to round, margin green or white, sometimes reflexed
Flower: perianth opening or not, 1.5–2.5 mm, white to red, midribs ± green; fertile stamens 3, 5, or 8, varying within plants
Fruit 1–2 mm, light brown to nearly black, shiny to sculptured in lines and dull
Ecology: Common. Vernally moist places
Elevation: 100–3300 m.
Bioregional distribution: Northwestern California, Cascade Range, Sierra Nevada, Transverse Ranges, Peninsular Ranges, Modoc Plateau
Distribution outside California: to British Columbia, Montana, Colorado, Arizona
Highly variable intergrading complex centered in MP, 1500 m. Sspp. may grow together, sometimes without intergrading. CA subspp. self-pollinating. Bracts may change dramatically with age; immature plants may not key.

Native

subsp. kelloggii (Greene) J.C. Hickman

Stem 1–15 cm
Inflorescence 3–15 mm, 5–15 mm wide; bracts 3–10 mm, smaller upward, spreading, all linear-lanceolate, margin green
Flower: perianth 1.5 mm, white to red; anthers 3
Fruit 1.5 mm, widely ovoid, light brown, ± shiny
Ecology: Common. Mtn meadows, seeps, rainpools
Elevation: 1500–3300 m.
Bioregional distribution: Northwestern California, Cascade Range, Sierra Nevada, Transverse Ranges, Peninsular Ranges
Distribution outside California: to British Columbia, Montana, Colorado, Arizona
Synonyms: P. k. Greene