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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, glandular, glaucous
Leaves basal; stipule 0; petiole indistinct; blade linear to obovate, hairy
Inflorescence open; bracts generally 3 per node, generally linear-lanceolate, generally fused at base, awned; involucre 1 per node, generally stalked, narrowly funnel-shaped to bell-shaped, teeth 3–36, awned; flowers 2–20 per involucre
Flower: perianth white to rose or pale yellow, hairy, lobes 6; stamens 9
Fruit golden-brown to dark brown. w North America., s South America
Etymology: (Latin: sharp box, from involucre)
Reference: [Ertter 1980 Brittonia 32:70–102]


O. perfoliata Torr. & A. Gray

Plant 6–20 cm, nearly glabrous or sparsely glandular
Leaf 1–6 cm, oblanceolate to oblong, ciliate
Inflorescence glandular on lower half of internodes; bracts fused around node, fused unit 1–2.5 cm diam; involucre sessile, narrowly funnel-shaped, involucral bracts 4, 2–5 mm, < half fused, awns 2–3 mm; flowers 5–10
Flower: perianth 1.5–2.5 mm, white to greenish yellow, hairy, lobes entire
Fruit 1.5–2 mm
Chromosomes: n=20
Ecology: Common. Creosote-bush or pinyon scrub, sandy to rocky soils
Elevation: 200–2000 m.
Bioregional distribution: s San Joaquin Valley, Great Basin Floristic Province, Mojave Desert
Distribution outside California: to Nevada, sw Utah, nw Arizona
Flowering time: Apr–Jul

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