ASTERACEAE

SUNFLOWER FAMILY

David J. Keil, Family Editor and author, except as specified

Annual to tree
Leaves basal or cauline, alternate to whorled, simple to compound
Inflorescence: 1° inflorescence a head, each resembling a flower, 1–many, generally arrayed in cymes, generally subtended by ± calyx-like involucre; flowers 1–many per head
Flowers bisexual, unisexual, or sterile, ± small, of several types; calyx 0 or modified into pappus of bristles, scales, or awns, which is generally persistent in fruit; corolla radial or bilateral (rarely 0), lobes generally (0)4–5; stamens 4–5, anthers generally fused into cylinder around style, often appendaged at tips, bases, or both, filaments generally free, generally attached to corolla near throat; pistil 1, ovary inferior, 1-chambered, 1-seeded, style 1, branches 2, generally hair-tufted at tip, stigmas 2, generally on inside of style branches
Fruit: achene, cylindric to ovoid, generally deciduous with pappus attached
Genera in family: ± 1300 genera, 21,000 species (largest family of dicots): worldwide. Largest family in CA. Also see tribal key to CA genera: Strother 1997 Madroño 44(1):1–28. See glossary p. 25 for illustrations of general family characteristics.

HOLOCARPHA

Annual, densely glandular, strongly scented
Leaves alternate or lower opposite, linear to oblanceolate, entire to lobed; upper reduced, often with axillary leaf clusters, tipped by open-pit glands
Inflorescence: heads radiate, in flat-topped to panicle-like clusters; phyllaries half-enclosing ray ovaries, falling with fruits, back with stalked, open-pit glands, tip cylindric, gland-tipped; receptacle chaffy
Ray flowers 3–16; ligules 3-lobed (middle narrowest), yellow
Disk flowers few–many, most sterile; corolla yellow; anther tips widely triangular; style branches tapered
Fruit: pappus 0; ray achenes ± 3-angled, short-beaked, dark; disk achenes ± club-shaped
Species in genus: 4 species: CA
Etymology: (Greek: wholly chaffy, from receptacle)
Reference: [Palmer 1982 PhD Univ CA Davis]
± identical forms often intersterile.

Native

H. virgata (A. Gray) D.D. Keck

Stems 2–12 dm; branches generally not overtopping main stem, soft-hairy and glandular below, canescent or short-bristly above, resinous
Leaves: lower 6–15 cm, linear, bristly, resinous; upper crowded
Inflorescence spike- or raceme-like; heads sessile or short-peduncled; peduncle bracts 2–5 mm, overlapping, appressed to involucre base, spreading to ± recurved, ± cylindric, generally gland-tipped; involucres 5–6 mm, ± obconic; phyllaries with 5–20 stout, gland-tipped projections, otherwise glabrous; receptacle 1–2 mm diam, nearly flat
Ray flowers 3–7; ligules 4–6 mm
Disk flowers 9–25; corollas 3.5–4.5 mm; anthers black
Fruit: ray achenes 2.4–3.5 mm
Chromosomes: 2n=8
Ecology: Grassland
Elevation: < 800 m.
Bioregional distribution: Inner North Coast Ranges, n&c Sierra Nevada Foothills, Great Central Valley, e Central Western California, c&s South Coast.