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Key to families | Table of families and genera

Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.

 

HELENIUM SNEEZEWEED

Mark W. Bierner


Annual, perennial herb, 10–160 cm. Stem: erect, unbranched or branched distally, generally ± winged by decurrent leaf bases, glabrous or ± hairy. Leaf: basal and cauline; basal, proximal cauline leaves often withered by flowering, alternate, simple, entire, toothed or lobed, glabrous or ± hairy, gland-dotted. Inflorescence: heads radiate or discoid, hemispheric to ovoid or ± spheric, 1 or generally in panicle-like or ± flat-topped clusters; involucre shallowly cup- or disk-like, phyllaries in 2 series (in California), free or ± basally fused, ± equal (or outer longer), generally reflexed in fruit; receptacle conic, ± spheric, hemispheric, or ovoid, pitted, epaleate. Ray flower: 0 or 7–34, pistillate (in California), corolla yellow (in California), ray fan-shaped, 3-lobed. Disk flower: 75–1000+; corolla generally 5-lobed, yellow, purple, or proximally yellow to yellow-green and distally ± brown or purple; anther tip triangular; style tips truncate. Fruit: obpyramidal, ribbed, glabrous or ± hairy; pappus of 5–12 membranous scales.
± 32 species: North America, South America. (Helen of Troy) [Bierner 2006 FNANM 21:426–435]
Unabridged references: [Bierner 1972 Brittonia 24:331–355]

Key to Helenium

1. Stem not winged; cauline leaves generally narrowly linear; annual ..... H. amarum var. amarum

1' Stem winged by decurrent leaf bases; cauline leaves generally wider; annual or per

2. Cauline leaf margin ± toothed ..... H. autumnale

2' Cauline leaf margin entire

3. Heads (1)4–20(30); ray corolla 3.8–10 mm (occasionally ray flowers 0); disk corolla generally 4-lobed, 1.6–2.7 mm; pappus scales 0.4–1 mm ..... H. puberulum

3' Heads 1–20; ray corolla 12–37 mm; disk corolla 5-lobed, 3–5.2 mm; pappus scales 1.3–4.5 mm

4. Peduncle sparsely to moderately hairy; pappus scales 1.3–2.2(2.7) mm; widespread but not North Coast ..... H. bigelovii

4' Peduncle generally densely hairy; pappus (2.5)3–4.5 mm; North Coast ..... H. bolanderi

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Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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