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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California

  • Up-to-date information about California vascular plants is available from the Jepson eFlora.



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.



Annual, biennial, perennial herb, generally from stout taproot, some dioecious, glabrous
Stem generally erect, generally unbranched below inflorescence, < 2 m, ± ridged, generally red-brown in fruit; nodes ± swollen
Leaves generally ± basal, alternate, petioled; stipules fused, sheathing stem above nodes, fracturing; blade < 50 cm
Inflorescence: bracted clusters generally arrayed in erect panicles
Flower generally bisexual, < 3 mm, generally green; perianth lobes 6, persistent, outer 3 in fruit ± inconspicuous, inner 3 in fruit enlarged, hardened, ± veiny, covering fruit, midrib often expanded into a tubercle; stamens 6; stigmas 3, fringed
Fruit brown, shiny
Etymology: (Latin: sorrel)
Reference: [Mitchell 1978 Brittonia 30:293–296]
Hybrids common. Mature inner perianth lobes generally required for identification. Some cultivated for vegetable greens. TOXIC in quantity to livestock; seldom eaten.


R. obtusifolius L.


Stem < 15 dm, stout
Leaves basal and cauline, < 75 cm; blade lance-ovate, cordate, flat, entire
Inflorescence open, interrupted below, ± leafless
Flower: inner perianth lobe 3–5 mm, narrowly ovate-triangular, teeth generally ± 0.5 mm (in some flowers 1–2 mm or 0), tubercle 1 (or 3, unequal)
Fruit 2–3 mm
Chromosomes: 2n=40
Ecology: Moist places
Elevation: < 1500 m.
Bioregional distribution: California
Distribution outside California: native to w Europe
Flowering time: Jun–Dec
Synonyms: subsp. agrestis (Fr.) Danser
Hybridizes with R. crispus , other Eur species

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