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.

PERITYLE

Annual, perennial herb, subshrubs, shrubs
Leaves opposite or alternate, simple to deeply divided or compound, sessile or petioled
Inflorescence: heads radiate, discoid or disciform, solitary or in cymes; peduncles short or long; involucre cylindric, hemispheric, or bell-shaped; phyllaries in 2–3 ± equal series, linear to ovate; receptacle flat to conic, naked
Ray flowers: ligules yellow or white
Disk flowers many; corollas yellow or white, 4-lobed; anther tips triangular; style tips tapered
Fruit linear to oblanceolate, very flat, sometimes weakly 3–4-angled; surface dark brown or black, glabrous or puberulent; margins generally ± thick, puberulent to strongly ciliate; pappus 0 or a crown of fringed scales and 0–2 slender bristles
Species in genus: ± 75 species: sw North America
Etymology: (Greek: around the margin, from thick fruit margin)
Reference: [Powell 1974 Rhodora 76:229–306]
Horticultural information: STBL.

Native

P. emoryi Torr.

Annual 2–60 cm, puberulent to rough-hairy and glandular
Stems simple to much-branched
Leaves generally alternate, petioled; blades 2–10 cm, ovate, round, or triangular, coarsely toothed to palmately lobed, teeth and lobes generally again toothed or lobed
Inflorescence: heads radiate (rarely disciform), 1–many; peduncles 0.1–7 cm; involucre hemispheric to bell-shaped; phyllaries many, 5–6 mm, lanceolate or oblanceolate to ovate
Ray flowers generally 8–12; ligules 1.5–4 mm, white, rarely vestigial
Disk flowers: corollas 2–2.5 mm, yellow
Fruit generally 2–3 mm; margins thin, ciliate; surfaces of ray achenes generally ± puberulent; surfaces of disk achenes generally glabrous; pappus scales well developed or vestigial, bristle 0 or 1, 1–2.5 mm
Chromosomes: 2n=64–72, 100–116
Ecology: Common. Desert plains, slopes, and washes
Elevation: < 1000 m.
Bioregional distribution: Desert (uncommon South Coast, Channel Islands)
Distribution outside California: Nevada, Arizona, n Mexico; also in w S.America
Flowering time: Feb–Jun