|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
AND IS MAINTAINED FOR ARCHIVAL PURPOSES ONLY
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.
Perennial from taproot and caudex
Stems 1several, erect
Leaves basal and cauline, alternate or opposite; petioles short to long; blades generally 3-veined, linear to ± ovate, entire, ± scabrous
Inflorescence: heads radiate, 1few, in cymes; peduncles long, with 0few leaf-like bracts; involucre hemispheric; phyllaries in 23 series, free; receptacle flat to ± convex, chaff scales folded around ovary, entire, obtuse, tip hairy
Ray flowers sterile; corolla yellow; style 0
Disk flowers many; corolla and anthers yellow or purple; style tips short-triangular
Fruit thick or compressed; pappus 0 or 2 awns 12 mm (sometimes also crown of low scales)
Species in genus: 8 species: w North America
Etymology: (Latin: diminutive of Helianthus )
Reference: [Weber 1952 Amer Midl Naturalist 48:135]
See the CNPS Inventory for information about endangerment and rarity.
Stems 15 dm, glabrous to coarsely hairy
Leaves: cauline few; petioles long; blades 26 cm wide, narrowly to widely elliptic
Inflorescence: head generally 1; peduncle 720 cm, stout, ± rough-hairy, often with 1few bracts near tip; involucre 2.54 cm diam; outer phyllaries generally leaf-like, 310 cm, 720 mm wide, curving up around head; inner phyllaries 22.5 cm, coarsely ciliate
Ray flowers 1321; ligules 13 cm
Disk flowers: corollas 67 mm, yellow; anthers yellow
Fruit 810 mm, obovate, glabrous; center thick; edges thin; pappus awns 0 or 2, < 1 mm
Ecology: Open, grassy sites
Elevation: 2001300 m.
Bioregional distribution: n San Francisco Bay Area
Horticultural information: In cultivation.