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.

MICROSERIS

Kenton L. Chambers

Annual or perennial herb, ± mealy (hairs drying as minute white scales); sap milky
Leaves mostly basal, generally linear to (ob)lanceolate, generally variably entire to pinnately lobed
Inflorescence: heads solitary, ligulate, ± nodding in bud; involucre generally fusiform to spheric; phyllaries in 2–several series, outer overlapping, inner often ± black-hairy; receptacle naked
Flowers 5–many; corollas white to orange, often reddish below, ligules = to >> involucre, readily withering
Fruit cylindric to fusiform, generally square-topped, not beaked; ribs ± 10, ± scabrous; pappus of generally 5–many ± lanceolate, bristle-tipped scales
Etymology: (Greek: small chicory)
Reference: [Chambers Contr Dudley Herb Stanford U: 1955 4:207–312 & 1957 5:57–68]
Hybridization common. Self-pollinating (annual) or self-incompatible and ± complex (perennial herb).

Native

M. laciniata (Hook.) Sch.Bip.

Perennial 15–100 cm, ± branched and leafy below
Leaf 10–50 cm
Inflorescence: involucre 14–30 mm; outer phyllaries linear to deltate, < to << inner
Flowers 13–100+; ligules yellow, >> involucre
Fruit 3.5–8 mm, not or barely wider at tip, gray to brown, smooth or outermost fruits scabrous on ribs; pappus scales 5–24, < 8 mm, white, bristles 4–12 mm, smooth to barbed
Chromosomes: 2n=18
Ecology: Open grassland, meadows, rocky slopes, forest edge
Elevation: < 2000 m.
Bioregional distribution: Northwestern California, High Cascade Range, Modoc Plateau
Distribution outside California: Oregon

Native

subsp. leptosepala (Nutt.) K.L. Chambers

Inflorescence: outer phyllaries linear to lanceolate, mealy, ± black-hairy, keel fleshy
Flowers 13–70
Fruit: pappus scales 5–10, < 1.5 mm; bristles smooth below
Ecology: Habitats of sp.
Bioregional distribution: Northwestern California
Horticultural information: TRY.