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.

HELIANTHUS

SUNFLOWER

Annual or perennial herb
Stems generally erect
Leaves opposite or alternate, generally reduced upward, often 3-veined from near base, generally rough-hairy
Inflorescence: heads radiate, solitary or in cymes; involucre bell-shaped to hemispheric; phyllaries in 1–3 generally ± equal series, free; receptacle flat to rounded; chaff scales 0–3-lobed
Ray flowers 10–many, sterile; ligules yellow
Disk flowers many; corollas yellow to red or purple, tube short, throat base often swollen, lobes triangular; style appendages triangular
Fruit oblanceolate to obovate, ± compressed; sides rounded; pappus generally of 2 deciduous, lanceolate to ovate scales (sometimes also 1–several shorter scales)
Species in genus: 67 species: Am
Etymology: (Greek: sun flower)
Reference: [Heiser 1969 Mem Torrey Bot Club 22(3):1–218]

Native

H. nuttallii Torr. & A. Gray

Perennial 5–40 dm, from clustered, tuber-like roots; rhizome short
Stems glabrous or hairy
Leaves alternate or opposite, subsessile; blade 10–20 cm, narrowly lanceolate to ovate, acute to acuminate, entire or serrate, glabrous to hairy
Inflorescence: heads few–many; peduncles 1–18 cm; involucre 1–2 cm diam; phyllaries ± erect, 8–16 mm, generally < 3 mm wide, ± linear, = or slightly > disk, glabrous or tomentose; chaff scales 8–12 mm, entire or 3-toothed, acute, short-rough-hairy
Ray flowers 12–20; ligules 15–25 mm
Disk flowers: corollas 5–6 mm, lobes yellow
Fruit 3–4 mm; pappus scales 3–4 mm (sometimes also with shorter scales)
Ecology: Damp meadows, marshes
Elevation: < 500 (c-w SW) or 1200–2500 m.
Bioregional distribution: c-w Southwestern California, San Gabriel Mountains, San Bernardino Mountains, Great Basin Floristic Province
Distribution outside California: to British Columbia, e Canada, New Mexico

Native

subsp. nuttallii

Stems glabrous to scabrous
Leaves: blade scabrous above, stiffly hairy below
Inflorescence: peduncles glabrous; phyllaries glabrous or strigose
Chromosomes: 2n=34
Ecology: Damp meadows
Elevation: 1200–2500 m.
Bioregional distribution: San Gabriel Mountains, San Bernardino Mountains, Great Basin Floristic Province
Distribution outside California: to British Columbia, e Canada, New Mexico
Flowering time: Jul–Sep
Horticultural information: IRR, SUN: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.