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.

HOLLISTERIA

Species in genus: 1 sp
Etymology: (Col. William W. Hollister, CA pioneer, 1818–1886)
Reference: [Reveal 1989 Phytologia 66:199–220]

Native

H. lanata S. Watson

Annual, spreading, 3–20 cm, tomentose
Leaves basal; stipule 0; petiole 0; blade 15–60 mm, generally linear, thinly hairy
Inflorescence 5–50 cm diam; bracts 3–4 per node, awned, the largest 7–20 mm, ± elliptic, others 2–5 mm, linear; involucral bracts 3–4, free, 1.5–2 mm, awned; flower 1 per involucre
Flower: perianth 1.5–2 mm, yellowish, woolly, lobes 6, outer 3 narrower; stamens 6–9
Fruit 1.7–2 mm, brown to dark black
Chromosomes: n=21
Ecology: UNCOMMON. Grassland in ± clay soils
Elevation: 15–975 m.
Bioregional distribution: s San Joaquin Valley, Inner South Coast Ranges.