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.

PSILOCARPHUS

WOOLLY-HEADS, WOOLLY MARBLES

James D. Morefield

Annual, gray to green, cobwebby to tomentose
Stems generally several from base, generally spreading, < 20 cm, ± forked; central axis generally 0 or not dominant
Leaves simple, generally opposite, ± sessile, < 3 cm, ± obtuse, entire (uppermost ± alternate or seeming whorled, generally ± appressed to heads)
Inflorescence: heads disciform, sessile, solitary or in small groups, generally spheric; bracts like leaves; phyllaries 0; receptacle 1–2 X > wide, ± obovoid, generally entire, chaffy; chaff scales each enclosing a pistillate flower, falling with a fruit, length generally < 3 X width, generally ± obovoid, bulged upward, woolly, net-veined, tip scarious-winged, offset to inner edge, generally ± 2/3 the distance from base to top of scale, projected inward, beak-like, hidden in head
Pistillate flowers in many series, each subtended by a chaff scale; corollas tubular
Disk flowers staminate, 2–10, not subtended by chaff scales; ovary vestigial
Fruit smooth, shiny; pappus 0
Species in genus: 3–5 ill-defined species: w North America, s South America
Etymology: (Greek: slender chaff)
Reference: [Cronquist 1950 Res Stud State Coll WA 18:71–89]
Spp. appear to intergrade, need detailed study.

Native

P. brevissimus Nutt.

Plants variously tomentose
Stems several from base or branched above, spreading to erect; central axis various
Leaves: uppermost generally lanceolate to ovate, longest 8–25 mm, 1.5–6 X > wide
Inflorescence: largest head 6–14 mm; longest chaff scale generally 2.8–4 mm
Disk flowers 0.8–1.6 mm, (4)5-lobed
Fruit 0.8–1.9 mm, ± obovoid
Ecology: Vernal pools and flats
Elevation: < 2500 m.
Bioregional distribution: California Floristic Province, Modoc Plateau
Distribution outside California: to Washington, Montana, Utah, nw Baja California; s S.America

Native

var. brevissimus

DWARF WOOLLY-HEADS

Plants generally densely shaggy-tomentose
Stems generally several from base, spreading; central stem 0 or not dominant
Leaves: longest of uppermost generally 8–15 mm, generally 1.5–4 X > wide
Inflorescence: largest head 6–9 mm, spheric; receptacle entire to shallowly lobed; longest chaff scale < 3 X > wide, ± obovoid, wing ± 2/3 distance from base to top of scale
Disk flowers (4)5-lobed
Chromosomes: 2n=28
Ecology: Habitats and range of sp
Elevation:
Bioregional distribution: California Floristic Province, Modoc Plateau Possible intermediates to P. tenellus var. t. have been called P. globiferus Nutt.