|Jepson Flora Project: Jepson Interchange|
|TREATMENT FROM THE JEPSON MANUAL (1993)||
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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California
For up-to-date information about California vascular plants, visit the Jepson eFlora.
Annual to tree
Leaves basal or cauline, alternate to whorled, simple to compound
Inflorescence: 1° inflorescence a head, each resembling a flower, 1many, generally arrayed in cymes, generally subtended by ± calyx-like involucre; flowers 1many 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)45; stamens 45, 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):128. See glossary p. 25 for illustrations of general family characteristics.
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 12 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, 210, not subtended by chaff scales; ovary vestigial
Fruit smooth, shiny; pappus 0
Species in genus: 35 ill-defined species: w North America, s South America
Etymology: (Greek: slender chaff)
Reference: [Cronquist 1950 Res Stud State Coll WA 18:7189]
Spp. appear to intergrade, need detailed study.
Plants variously tomentose
Stems generally several from base, spreading; central axis 0 or not dominant
Leaves: uppermost oblanceolate to obovate, longest < 16 mm, generally 1.55 X > wide
Inflorescence: largest head < 6 mm; longest chaff scale generally 1.82.7 mm
Disk flowers 0.81.5 mm, 45-lobed
Fruit 0.61.2 mm, ± obovoid
Ecology: Vernal pools, coastal dunes, dry disturbed soil
Elevation: < 2000 m.
Bioregional distribution: California Floristic Province
Distribution outside California: to British Columbia, Idaho, nw Baja California, also in c Chile
Plants variously tomentose
Leaves: uppermost ± appressed to and concealing heads, ovate to widely elliptic, generally 1.52 X > wide
Disk flowers generally 4-lobed
Ecology: UNCOMMON. Vernal pools, coastal dunes
Elevation: 0700 m.
Bioregional distribution: c&s Sierra Nevada Foothills, San Joaquin Valley, Central Coast, San Francisco Bay Area
Distribution outside California: c Chile
Synonyms: var. tenuis (Eastw.) Cronquist; P. globiferus Nutt. misapplied
A similar SnBr form seems best assigned to P. brevissimus var. b.
|YOU CAN HELP US make sure that our distributional information is correct and current. If you know that a plant occurs in a wild, reproducing state in a Jepson bioregion NOT highlighted on the map, please contact us with that information. Please realize that we cannot incorporate range extensions without access to a voucher specimen, which should (ultimately) be deposited in an herbarium. You can send the pressed, dried collection (with complete locality information indicated) to us (e-mail us for details) or refer us to an accessioned herbarium specimen. Non-occurrence of a plant in an indicated area is difficult to document, but we will especially value your input on those types of possible errors (see automatic conversion of distribution data to maps).|