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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.

 

PENTACHAETA

David J. Keil & Meredith A. Lane


Annual from slender taproot, ± hairy (but appearing glabrous). Stem: generally simple or branching proximally, erect, generally flexible, glabrous to hairy, green to ± red. Leaf: generally narrowly linear, ciliate, green. Inflorescence: heads radiate, disciform, or discoid, nodding in bud, 1 or in open, ± flat-topped cluster; peduncle slender; involucre 3–7 mm, generally bell-shaped; phyllaries in 2–3(4) series, graduated or ± equal, lanceolate to (ob)ovate, green, margins widely scarious; receptacle flat to slightly convex, epaleate. Ray flower: present or 0, or corolla reduced to tube; corolla white, yellow, 2-colored yellow and white, or ± red. Disk flower: 4–90+; corolla yellow to ± red or maroon; style tips linear, acute. Fruit: 1.5–3 mm, oblong-fusiform, generally compressed, generally hairy; pappus of 0–20 fragile, slender bristles.
6 species: California, northwestern Baja California. (Greek: five bristles, from pappus) [Keil 2007 Madroño 54:343–344; Nesom 2006 FNANM 20:46–48] Similar, closely related to Rigiopappus, Tracyina.
Unabridged references: [Van Horn 1973 Univ Calif Publ Bot 65:1–41]

Key to Pentachaeta

1. Well developed ray flowers 0; ray of pistillate flowers 0 or pistillate flowers 0

2. Disk flowers generally 4; corolla 3-lobed ..... P. alsinoides

2' Disk flowers 6–34; corolla 5-lobed ..... P. exilis subsp. exilis

1' Well developed ray flowers generally present, ray evident

3. Ray flowers white, ray sometimes ± red abaxially; pappus bristles present or 0

4. Ray flowers 7–16; peduncle glabrous to short-hairy ..... P. bellidiflora

4' Ray flowers (0)1–3; peduncle soft-shaggy-hairy ..... P. exilis subsp. aeolica

3' Ray flowers generally yellow or proximally yellow, distally white, sometimes ± brown-orange; pappus bristles present

5. Ray flowers 7–12, disk flowers 10–23; largest leaves < 2.5 cm ..... P. fragilis

5' Ray flowers 14–52, disk flowers 30–91; largest leaves 2.5–5.5 cm

6. Phyllaries lanceolate, soft-shaggy-hairy; pappus bristles 8–12 ..... P. lyonii

6' Phyllaries narrowly to widely-elliptic, glabrous or sparsely short-hairy; pappus bristles 5–8 ..... P. aurea

7. Ray proximally yellow, distally white ..... subsp. allenii

7' Ray yellow to orange ..... subsp. aurea

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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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