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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.

 

TRISETUM

Robert E. Preston & Dieter H. Wilken


Annual, perennial herb. Stem: ascending to erect, generally clumped. Leaf: generally basal and cauline; ligule membranous, obtuse to truncate, toothed, tip ciliate or not; blade flat to inrolled. Inflorescence: panicle- to spike-like, open to compact, cylindric to narrowly conic. Spikelet: glumes ± unequal, generally <= lower floret, keeled, acute, lower 1-veined, upper 3-veined; axis stiff- to soft-hairy, generally prolonged behind upper floret, bristly or with vestigial floret; florets 2–3, bisexual, breaking above glumes and between florets (sometimes below glumes); callus short-hairy; lemma ± keeled, tip 2-bristled or not, awned on back near tip or not, awn straight or wavy to bent; palea = or < lemma; ovary glabrous or with short, stiff hairs at tip.
70–75 species: worldwide (except Africa) temperate, subarctic, alpine. (Latin: 3 bristles, from its 3-awned lemma) [Rumely 2007 FNANM 24:744–753] Some species intergrade; needs study in western North America. Trisetum flavescens (L.) P. Beauv. extirpated, last collected in California 1917.
Unabridged references: [Finot et al. 2006 Sida 21:1419–1453]

Key to Trisetum

1. Lemma awn 0(2) mm ..... T. wolfii

1' Lemma awn 4–12 mm

2. Inflorescence generally panicle-like, ± dense to open; awns generally > 7 mm; ovary hairy at tip

3. Florets generally to base of panicle branches; lower inflorescence branches ascending to erect; lower glume 3–5 mm ..... T. canescens

3' Florets only at tips of panicle branches; lower inflorescence branches generally spreading; lower glume < 3 mm ..... T. cernuum

2' Inflorescence generally spike-like, dense; awns generally <= 7 mm; ovary glabrous at tip

4. Panicle 8–23 cm, interrupted; leaves densely soft-hairy; upper glumes 5.5–7 mm ..... T. projectum

4' Panicle 2.5–7(10) mm, not interrupted; leaves glabrous or densely soft-hairy; upper glumes 4–5 mm ..... T. spicatum

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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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