Muhlenbergia Schreb., Gen. Pl. 1: 44. 1789.

Peterson, Paul M., Vega, Isidoro Sanchez, Romaschenko, Konstantin, Giraldo-Canas, Diego & Rodriguez, Nancy F. Refulio, 2018, Revision of Muhlenbergia (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) in Peru: classification, phylogeny, and a new species, M. romaschenkoi, PhytoKeys 114, pp. 123-206 : 129-131

Muhlenbergia Schreb., Gen. Pl. 1: 44. 1789.

Dilepyrum Michx., Fl. Bor.-Amer. 1: 40. 1803. Type: Dilepyrum minutiflorum Michx. (= Muhlenbergia schreberi J. F. Gmel.).

Aegopogon Humb. & Bonpl. ex Willd., Sp. Pl. 4 (2): 899. 1805 [1806] Type: Aegopogon cenchroides Humb. & Bonpl. ex Willd. [≡ Muhlenbergia cenchroides (Humb. & Bonpl. ex Willd.) P.M. Peterson].

Podosemum Desv., Nouv. Bull. Sci. Soc. Philom. Paris 2: 188. 1810. Type: Podosemum capillare (Lam.) Desv. [= Muhlenbergia capillaris (Lam.) Trin.].

Clomena P. Beauv., Ess. Agrostogr. 28. 1812. Type: Clomena peruviana P. Beauv. [≡ Muhlenbergia peruviana (P. Beauv.) Steud.].

Tosagris P. Beauv., Ess. Agrostogr. 29. 1812. Type: Tosagris agrostidea P. Beauv. [= Muhlenbergia capillaris (Lam.) Trin.].

Trichochloa P. Beauv., Ess. Agrostogr. 29. 1812. Type: Trichochloa purpurea P. Beauv. [= Muhlenbergia expansa (Poir.) Trin.].

Podosaemum Kunth, Mem. Mus. Hist. Nat. 2: 72. 1815; orth. var. Podosemum.

Hymenothecium Lag., Gen. Sp. Pl. 4. 1816. Lectotype: Cynosurus tenellus Cav. ex DC., designated by Hitchcock 1920: 169 [≡ Lamarckia tenella DC. ≡ Hymenothecium tenellum (Cav. ex DC.) Lag. = Muhlenbergia uniseta (Lag.) Columbus].

Lycurus Kunth, Nov. Gen. Sp. 1: 141. 1815 [1816]. Lectotype: Lycurus phleoides Kunth, designated by Hitchcock 1920: 139 [≡ Muhlenbergia phleoides (Kunth) Columbus].

Anthipsimus Raf., J. Phys. Chim. Hist. Nat. Arts 89: 105. 1819. Type: Anthipsimus gonopodus Raf. (= Muhlenbergia schreberi J.F. Gmel.).

Sericrostis Raf., Neogenyton 4. 1825. Lectotype: Stipa sericea Michx, designated by Pfeiffer 1874: 1142 [≡ Muhlenbergia sericea (Michx.) P.M. Peterson].

Pereilema J. Presl, Reliq. Haenk. 1 (4-5): 233.1830. Type: Pereilema crinitum J. Presl (≡ Muhlenbergia pereilema P.M.Peterson).

Epicampes J. Presl, Reliq. Haenk. 1 (4-5): 235. 1830. Type: Epicampes stricta J. Presl [= Muhlenbergia robusta (E. Fourn.) Hitchc.].

Dactylogramma Link, Hort. Berol. 2: 248. 1833. Type: Dactylogramma cinnoides Link [= Muhlenbergia glomerata (Willd.) Trin.].

Calycodon Nutt., Proc. Acad. Nat. Sci. Philadelphia 4: 23. 1848. Type: Calycodon montanum Nutt. [≡ Muhlenbergia montana (Nutt.) Hitchc.].

Pleopogon Nutt., Proc. Acad. Nat. Sci. Philadelphia 4: 25. 1848. Type: Pleopogon setosum Nutt. [≡ Lycurus setosus (Nutt.) C.G. Reeder = Muhlenbergia alopecuroides (Griseb.) P.M. Peterson & Columbus].

Schedonnardus Steud., Syn. Pl. Glumac. 1: 146. 1854. Type: Schedonnardus texanus Steud. [ Spirochloe paniculata Nutt. = Schedonnardus paniculatus (Nutt.) Branner & Coville = Muhlenbergia paniculata (Nutt.) Columbus].

Vaseya Thurb., Proc. Acad. Nat. Sci. Philadelphia 15: 79. 1863. Type: Vaseya comata Thurb. [= Muhlenbergia andina (Nutt.) Hitchc.].

Chaboissaea E. Fourn., Mexic. Pl. 2: 112. 1886. Type: Chaboissaea ligulata E. Fourn. [≡ Muhlenbergia ligulata (E. Fourn.) Scribn. & Merr.].

Crypsinna E. Fourn., Mexic. Pl. 2: 90. 1886. Lectotype: Crypsis macroura Kunth, designated by Hitchcock 1920: 144. [≡ Crypsinna macroura (Kunth) E. Fourn.≡ Muhlenbergia macroura (Kunth) Hitchc.].

Redfieldia Vasey, Bull. Torrey Bot. Club 14: 133. 1887. Type: Graphephorum flexuosum Thurb. ex A. Gray [≡ Redfieldia flexuosa (Thurb. ex A. Gray) Vasey ≡ Muhlenbergia multiflora Columbus].

Bealia Scribn., True Grasses 104, f. 45a. 1890. Type: Bealia mexicana Scribn. (≡ Muhlenbergia biloba Hitchc.).

Blepharoneuron Nash, Bull. Torrey Bot. Club 25(2): 88. 1898. Lectotype: Vilfa tricholepis Torr., designated by Peterson and Annable 1990: 522 [≡ Blepharoneuron tricholepis (Torr.) Nash ≡ Muhlenbergia tricholepis (Torr.) Columbus].

Schaffnerella Nash, N. Amer. Fl. 17(2): 141. 1912. Type: Schaffnera gracilis Benth. [≡ Schaffnerella gracilis (Benth.) Nash ≡ Muhlenbergia spatha Columbus].

Description.

Plants annual or perennial; synoecious sometimes andromonoecious; sometimes rhizomatous, often cespitose, sometimes mat-forming, rarely stoloniferous. Culms 2-300 cm, erect, geniculate or decumbent, usually herbaceous, sometimes becoming woody. Sheaths open, overlapping below; ligules membranous or hyaline (rarely firm or coriaceous), acuminate to truncate, sometimes minutely ciliolate, sometimes with lateral lobes longer than the central portion; blades narrow, flat, folded, or involute, sometimes arcuate. Inflorescences terminal, sometimes also axillary, open to contracted, raceme-like or spike-like panicles; cleistogamous panicles sometimes present in the axils of the lower cauline leaves, enclosed by a tightly rolled, somewhat indurate sheath; disarticulation usually above the glumes, occasionally below the pedicels. Spikelets mostly perfect with 1 (2-6) florets, sometimes staminate or sterile, occasionally paired or in groups of threes then the central spikelet perfect and the lateral ones staminate or sterile; chasmogamous, rarely cleistogamous; glumes usually (0)1(2-3)-veined, apices entire, erose or toothed, truncate to acuminate, sometimes mucronate or awned from the midvein, occasionally awned from the lateral veins; lower glumes sometimes rudimentary or absent, occasionally bifid; upper glumes shorter than to longer than the florets; calluses poorly developed, glabrous or with a few hairs; lemmas glabrous, scabrous or with short hairs, 3-veined (rarely appearing 5-veined), apices awned from the midvein, mucronate or unawned; awns, if present, straight, flexuous, sinuous or curled, sometimes borne between 2 minute teeth, lateral veins occasionally extended into awns; paleas shorter than or equal to the lemmas, 2-veined, apices; anthers (1-2)3, purple, orange, yellow, olivaceous or whitish; ovary with 2 styles, stigmas plumose. Caryopses elongate, fusiform or elliptic, slightly dorsally compressed, rarely laterally compressed, glabrous; hilum short; pericarp fused.

Chromosome base number is × = (8 or 9) 10 and these are relatively small in size.

Distribution.

The genus is primarily distributed in the Western Hemisphere in North Central and South America. There are also seven species known to occur in south-eastern Asia, six of these are found in China ( Wu and Peterson 2006).

Ecology.

The species occur in open habitats in deserts, grasslands, sclerophllous scrubland and margins of forests often in xeric to meso-xeric habitats from near sea level to more than 4000 m.

Etymology.

Named for Gotthilf Heinrich Ernst Muhlenberg (1753-1815), a Lutheran minister and pioneering botanist of Pennsylvania, USA.