Jepson Herbarium
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Annual to woody per; roots generally fibrous.
Stem: generally round, hollow; nodes swollen, solid.
Leaf: alternate, 2-ranked, generally linear, parallel-veined; sheath generally open; ligule membranous or hairy, at blade base.
Inflorescence: various (of generally many spikelets).
Spikelet: glumes generally 2; florets ( lemma, palea, flower) 1–many; lemma generally membranous, sometimes glume-like; palea generally ± transparent, ± enclosed by lemma.
Flower: generally bisexual, minute; perianth vestigial; stamens generally 3; stigmas generally 2, generally plumose.
Fruit: grain (rarely achene-like).
650–900 genera; ± 10550 species: worldwide; greatest economic importance of any family (wheat, rice, maize, millet, sorghum, sugar cane, forage crops, ornamental, weeds; thatching, weaving, building materials). [Barkworth et al. 2003 FNANM:25; Barkworth et al. 2007 FNANM:24] Generally wind-pollinated. Achnatherum, Ampelodesmos, Hesperostipa, Nassella, Piptatherum, Piptochaetium, Ptilagrostis moved to Stipa; Elytrigia, Leymus, Pascopyrum, Pseudoroegneria, Taeniatherum to Elymus; Hierochloe to Anthoxanthum; Lolium, Vulpia to Festuca; Lycurus to Muhlenbergia; Monanthochloe to Distichlis; Pleuraphis to Hilaria; Rhynchelytrum to Melinis. The following taxa (in genera not included here), recorded in CA from historical collections or reported in literature, are extirpated, lacking vouchers, or not considered naturalized: Acrachne racemosa (Roth) Ohwi, Allolepis texana (Vasey) Soderstr. & H.F. Decker, Amphibromus nervosus (Hook. f.) Baill., Axonopus affinis Chase, Axonopus fissifolius (Raddi) Kuhlm., Coix lacryma-jobi L., Cutandia memphitica (Spreng.) K. Richt., Dinebra retroflexa (Vahl) Panz., Eremochloa ciliaris (L.) Merr., Eustachys distichophylla (Lag.) Nees, Gaudinia fragilis (L.) P. Beauv., Miscanthus sinensis Andersson, Neyraudia arundinacea (L.) Henrard, Phyllostachys aurea Rivière & C. Rivière, Phyllostachys bambusoides Siebold & Zuccarini, Rottboellia cochinchinensis (Lour.) Clayton, Schedonnardus paniculatus (Nutt.) Branner & Coville, Schizachyrium cirratum (Hack.) Wooton & Standl., Schizachyrium scoparium (Michx.) Nash, Themeda quadrivalvis (L.) Kuntze, Thysanolaena latifolia (Hornem.) Honda, Tribolium obliterum (Hemsl.) Renvoize, Zea mays L., Zizania palustris L. var. interior (Fassett) Dore, Zoysia japonica Steud. Paspalum pubiflorum E. Fourn., Paspalum quadrifarium Lam., are now reported for s CA (J Bot Res Inst Texas 4:761–770). See Glossary p. 30 for illustrations of general family characteristics. —Scientific Editors: James P. Smith, Jr., J. Travis Columbus, Dieter H. Wilken.
Unabridged references: [Hitchcock 1951 Manual grasses US, USDA Misc Publ 200; Clayton & Renvoise 1986 Kew Bull Add Series 13]

Key to Poaceae

Annual, perennial herb, rhizomes 0 to well developed.
Stem: generally bent at base or erect, generally tufted.
Leaf: auricles present, occasionally small, fragile; ligule membranous, truncate to obtuse; blade flat, folded, or rolled.
Inflorescence: spike-like ( raceme-like or panicle-like), open to dense; axis generally remaining intact with age; spikelets 1–3(7) at all or most nodes, generally ascending.
Spikelet: compressed laterally, glumes generally lanceolate to awn-like, occasionally 0, awned from tip or not; florets 1–11; breaking apart above glumes and between florets; lemma generally > glumes, generally rounded, 5–7-veined, tip acute to awned, awn straight or curved outward; palea <, =, or > lemma or 0; anthers 3(1), 1–8 mm.
± 235 species: temperate worldwide. (Greek: covered, a reference to grain being tightly covered by palea and lemma) [Barkworth 2007 FNANM 24:283–287, 348–351, 353–369, 373–378] References to number of spikelets per node is best understood as "most, if not all" and best determined by examining nodes in middle of inflorescence. Intergeneric and interspecific hybrids, along with effects of soil moisture on plant growth, render keys even more challenging and frustrating than usual. As treated here, genus includes taxa previously assigned to Agropyron (in part), Elytrigia, Leymus, Pascopyrum, Pseudoroegneria, and Taeniatherum. Elymus ×aristatus Merr., Elymus arizonicus (Scribn. & J.G. Sm.) Gould, Elymus canadensis L., Elymus interruptus Buckley, Agropyron junceum (L.) P. Beauv. [Thinopyrum junceum (L.) Á. Löve], Elytrigia juncea (L.) Nevski subsp. boreali-atlantica (Simonet & Guin.) Hylander [Elymus farctus (Viv.) Melderis subsp. boreo-atlanticus (Simonet & Guin.) Melderis], and Elymus pycnanthus (Godr.) Melderis [Thinopyrum pycnanthum (Godr.) Barkworth] have been reported for CA, may occur sporadically, but do not appear to have become naturalized. Intergeneric hybrids involving Hordeum constitute the genus ×Elyhordeum. They are cited in species descriptions.
Unabridged references: [Barkworth & Dewey 1985 Amer J Bot 72:767–776; Barkworth et al. 2007 FNANM 24:288–343; Carlson 2007 FNANM 24:279–282; Gould 1947 Madroño 9:120–128; Wipff 2007 FNANM 24:257, 258]

Plant cespitose, sometimes rhizomatous.
Stem: 3–10 dm, slender, green or glaucous.
Leaf: auricles well developed; ligule 0.1–0.4 mm; blade 2–6 mm wide, flat to loosely rolled.
Inflorescence: 8–16 cm, narrow; spikelets 1 per node; middle internodes 0.8–2.5 cm.
Spikelet: 8–22(25) mm; glumes 6–13 mm, 0.9–2.2 mm wide, ± 1/2 spikelet length, veins evenly glabrous or scabrous; florets 4–9; lemma 9–14 mm, awn 0–25 mm, strongly divergent.
2n=14,28. Sagebrush steppe, open woodland; 670–2190 m. Klamath Ranges, North Coast Ranges, Cascade Range, n&c Sierra Nevada, Modoc Plateau;

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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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Bioregions in which taxon occurs	Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
Chart based on elevation range in Manual and elevations and coordinates of CCH records. Data provided by the participants of the Consortium of California Herbaria. Note: About half of the CCH records include both elevation and coordinates.	Data provided by the participants of the Consortium of California Herbaria. View all CCH records   CCH collections by month Duplicates counted once; synonyms included. Species do not include records of infraspecific taxa. Blue line denotes Manual flowering time.