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| Jepson eFlora
Key to families | Table of families and genera This text currently parallels The Jepson Manual: Vascular Plants of California, Second Edition that is now available at the University of California Press. Text appearing in blue on this page will not appear in the printed book; it will be displayed only on the Web. 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. |
Annual, perennial herb, occasionally mat-like, often rhizomed.
Stem: decumbent to erect, ± clumped.
Leaf: basal and cauline; sheath open; ligule membranous, entire to irregularly toothed, occasionally with 1 large tooth on each side; blade flat to rolled.
Inflorescence: panicle-like, narrow to open; branches spreading to appressed.
Spikelet: generally single ( bisexual) occasionally paired ( bisexual, staminate or sterile); glumes subequal, generally 1–3-veined, short-pointed to awned, upper glume occasionally 3-veined; florets 1, occasionally 2; axis breaking above glumes; lemma short-pointed to awned, glabrous to hairy, 3-veined; palea <= lemma.
Fruit: ± fusiform, red-brown, generally falling with lemma and palea.
173 species: temperate America, s Asia. (G.H.E. Muhlenberg, PA botanist, 1753–1815) {hort link} Reports of Muhlenbergia dumosa Vasey, Muhlenbergia glauca (Nees) B.D. Jacks., Muhlenbergia thurberi (Scribn.) Rydb. have proved to be erroneous.
Unabridged references: [Peterson 2003 FNANM 24:145–200; Reeder 1981 in Gould and Moran 1981 San Diego Soc Nat Hist Memoir 12:67–78]
1. Annual
2. Lemma awned, awn 1–3 cm, lemma 2.5–6 mm
3. Lemma generally 4.5–6 mm; inflorescence generally < 1.5 cm wide, branches closely appressed; glumes generally 1–2 mm ..... M. appressa
3' Lemma generally 2.5–4.5 mm; inflorescence 1–5 cm wide, branches spreading to ascending; glumes generally < 1 mm ..... M. microsperma (2)
2' Lemma short-awned, awn < 1 mm, or awn 0; lemma < 2.5 mm
4. Infl narrow, < 1 cm wide; branches closely appressed; stems often rooting at lower nodes ..... M. filiformis (2)
4' Infl open, 1.5–8 cm wide; branches reflexed, ascending to spreading; stems not rooting at lower nodes
5. Infl branches stiffly spreading to reflexed ± 90° from axis; glumes glabrous; ligule teeth 2, 1 on each side ..... M. fragilis
5' Infl branches ascending < 80° from axis; glume tip short-hairy; ligule truncate to obtuse, irregularly short-toothed ..... M. minutissima
1' Perennial
6. Lemma awn 0 or short-awned, awn < 1 mm
7. Infl 5–14 cm wide, open, branches spreading ..... M. asperifolia
7' Infl <= 4 cm wide, narrow, branches ascending to appressed, occasionally loosely spreading
8. Rhizomes creeping, ± scaly; stems ± decumbent to erect
9. Glumes 2.5–4 mm, ± = lemma; lower 1/2 lemma short-soft-hairy ..... M. californica (2)
9' Glumes 0.5–1.8 mm, ± 1/2 lemma; lemma glabrous to ± scabrous
10. Ligule generally 1–2.5 mm; inflorescence axis generally obscured by branches, spikelets ..... M. richardsonis
10' Ligule generally < 1 mm; inflorescence axis generally visible between branches ..... M. utilis
8' Rhizomes 0; stems clumped or decumbent and ± rooting at nodes
11. Blade < 4 cm; lemma generally < 2 mm; stem generally < 3 dm ..... M. filiformis (2)
11' Blade >= 5 cm; lemma generally > 2.5 mm; stem 2–15 dm
12. Infl <= 15 cm, 1.5–4 cm wide; branches loosely flowered ..... M. jonesii
12' Infl 15–60 cm, <= 1.2 cm wide; branches densely flowered ..... M. rigens
6' Lemma awn 1–30 mm
13. Infl open, 6–15 cm wide, branches spreading ..... M. porteri
13' Infl generally < 6 cm wide, branches ascending to appressed, occasionally spreading
14. Glumes 1 or 2, generally < 0.5 mm, vein 0 ..... [M. schreberi]
14' Glumes 2, generally > 0.5 mm, vein(s) evident
15. Rhizome generally scaly, creeping
16. Blade generally rolled, < 2 mm wide; anther purple, 1.5–3 mm
17. Lemma, palea short-soft-hairy on lower 1/2; stems loosely clumped, decumbent ..... M. arsenei (2)
17' Lemma base sparsely short-hairy; palea glabrous to ± scabrous; stems erect, ± rooting at lower nodes ..... M. pauciflora (2)
16' Blade generally flat, >= 2 mm wide; anther yellow, generally <= 1.5 mm
18. Hairs at lemma base 2–3.5 mm ..... M. andina
18' Hairs at lemma base < 1.5 mm
19. Lemma awn generally < 2.2 mm; anther 1–1.5 mm ..... M. californica (2)
19' Lemma awn 2.5–9 mm; anther < 0.5 mm ..... M. mexicana
15' Rhizomes 0
20. Upper glume 3-veined, 3-toothed ..... M. montana
20' Upper glume generally 1-veined, obtuse, acute, or awned
21. Lower glume 2-veined, 2-awned; inflorescence 5–8 mm wide, spike-like, dense ..... M. alopecuroides
21' Lower glume 1-veined, with 1 awn or awnless; inflorescence 5–30 mm wide, dense to loose
22. Glumes 0.5–1 mm, obtuse; cleistogamous spikelets generally present in lowermost stem axils ..... M. microsperma (2)
22' Glumes generally 1.5–3.5 mm, acute, acuminate, or awned; cleistogamous spikelets 0
23. Lemma, palea short-soft-hairy on lower 1/2; stems loosely clumped, decumbent ..... M. arsenei (2)
23' Lemma base sparsely short-hairy; palea glabrous to ± scabrous; stems erect, ± rooting at lower nodes ..... M. pauciflora (2)
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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