Flora of the Carolinas, Virginia, and Georgia, Working Draft of 17 March 2004 -- POACEAE POACEAE or GRAMINEAE (Grass Family) A family of about 670 genera and 10,000 species, cosmopolitan. References: Flora of North America Editorial Committee (2003a)=FNA; Hitchcock and Chase (1950)=HC; Blomquist (1948). [note: only a small portion of the key to genera complete] Key A -- tribe Andropogoneae 1 Leaves ovate-lanceolate, 2-10 cm long, 2.5-7× as long as wide; plants weak-stemmed annuals, branching, decumbent, rooting at the lower nodes; [plants alien weeds]. 2 Leaves cordate-clasping at base; spikelets not paired, unaccompanied by a vestige . Arthraxon 2 Leaves tapering to a broadly cuneate base; spikelets paired (one of the pair sometimes vestigial) . Microstegium 1 Leaves lanceolate to linear, either longer or proportionately narrower; plants either perennial or coarse annuals with erect and mostly unbranched culms. 3 Spikelets embedded in the thickened rachis (the inflorescence thus like an ear of corn), or fitting into grooves in the thickened rachis (the inflorescence thus cylindrical and resembling a rat's tail), or the pistillate inflorescences enclosed in a hard, bead-like, pearly-white, modified bract. 4 Spikelets unisexual, with male and female spikelets in separate inflorescences or in different parts of the same inflorescence. 5 Internode narrower than and more-or-less enclosed by the female spikelet . Coix 5 Internode broader than and more-or-less enclosing the female spikelet. 6 Racemes of mixed sex, female below, male above . Tripsacum 6 Racemes of single sex............................................................. Zea 4 Spikelets, or at least one of each pair, bisexual. 7 Pedicels fused to the internode; [plant a coarse alien grass of disturbed habitats] . Rottboellia 7 Pedicels free from the internodes; [plant either a native coarse grass of pinelands or prairie-like areas, or a short alien grass of lawns and disturbed areas]. 8 Sessile spikelet smooth or pitted; culms 50-200 cm tall; [plant a native grass of pinelands or prairie-like areas] .................................................................. Coelorachis 8 Sessile spikelet with pectinate margins; culms 5-40 cm tall; [plant an alien grass of lawns and disturbed areas] .................................................................. Eremochloa 3 Spikelets not embedded or fitting into grooves in the rachis, the rachis slender (the spikelets visibly separate and often pedicelled). 9 Pedicelled spikelet similar to the sessile spikelet, both fertile. 10 Spikelets falling in pairs together with sections of the disarticulating rachis . Saccharum 10 Spikelets falling separately from the persistent rachis. 11 Panicle contracted, spikelike; glumes membranous . Imperata 11 Panicle loose; glumes cartilaginous or coriaceous . Miscanthus 9 Pedicelled spikelet differing from the sessile in shape and sex (sometimes represented only by a pedicel). 12 Spikelets awned, the awn 10-20 cm long. 13 First glume lacking glands; panicle open, the branches 5-8 cm long . Chrysopogon 13 First glume with a row of punctate, concave glands; panicle contracted, spikelike . Heteropogon 12 Spikelets awned or not, if awned the awn less than 5 cm long. 14 Inflorescence a panicle, the branches not subtended by sheaths. 15 Pedicelled spikelet represented by pedicel only; apex of sheath bearing 2 auricles 1-10 mm long; [native]............................................................. Sorghastrum 15 Pedicelled spikelet present, staminate; apex of sheath truncate; [alien] . Sorghum 14 Inflorescence of 1-13 digitate (whorled) racemes borne at the summit of a peduncle, the peduncle subtended by a raceme sheath. 16 Racemes 1 per peduncle and raceme sheath . Schizachyrium 16 Racemes 2-13 per peduncle and raceme sheath. 17 Pedicels of the pedicelled (reduced or absent) spikelets terete or slightly flattened and grooved on one side only...................................................Andropogon 17 Pedicels of the pedicelled (reduced or absent) spikelets strongly flattened and grooved on both sides, the central portion thin or membranous . Bothriochloa Aegilops Linnaeus 1753 (Goat Grass) References: Tucker (1996)=Z. 1 Spikelets cylindric; glumes with 4 awns; rachis disarticulating at maturity . Ae. cylindrica 1 Spikelets nearly ovate; glumes with 1 awn; rachis not disarticulating at maturity . Ae. neglecta 734 Flora of the Carolinas, Virginia, and Georgia, Working Draft of 17 March 2004 -- POACEAE * Aegilops cylindrica Host, Jointed Goat Grass. Mt, Pd (VA): disturbed areas; uncommon, introduced from s. Europe. [= C, F, G, HC, K, Z] * Aegilops neglecta Req. ex Bertoloni, Small Goat Grass. Cp (VA): disturbed areas; rare, introduced from s. Europe. reported from Arlington County, VA. [= Z; Ae. ovata Linnaeus -- C, G, HC, apparently misapplied; Ae. geniculata Roth -- K, apparently misapplied] Agropyron Gaertner 1770 (see Elymus, Elytrigia, Pascopyrum) Agrostis Linnaeus (Bentgrass) (also see Polypogon) References: Tucker (1996)=Z. 1 Palea 1/2-3/4 as long as the lemma, 0.6-1.2 mm long; plants introduced, often (though not always) in disturbed habitats; plants flowering (collectively) June-October; [subgenus Agrostis]. 2 Ligule mostly 0.5-2 mm long, truncate; panicle branches naked towards the base, diffuse when in fruit, the spikelets well- separated ........................................................................... A. capillaris 2 Ligule mostly 2.5-6 mm long, acute, rounded, or truncate; panicle branches (some of them) with spikelets to near the base, the spikelets usually agglomerated. 3 Leaves 3-8 mm wide; inflorescence triangular-ovoid, the branches widely spreading at maturity, usually reddish; plant with rhizomes, without stolons ....................................................A. gigantea 3 Leaves mostly 1-3 mm wide; inflorescence narrowly ovoid, the branches ascending at maturity, usually tan; plant without rhizomes, with or without stolons. 4 Stolons well developed; leaves mostly less than 5 cm long . A. stolonifera var. palustris 4 Stolons poorly developed or absent; leaves mostly more than 7 cm long . A. stolonifera var. stolonifera 1 Palea less than 2/5 as long as the lemma, 0-0.5 mm long; plants native, typically in more or less natural habitats; plants flowering (collectively ) March-November; [subgenus Vilfa]. 5 Lemma usually awned (sometimes unawned), the awn inserted near the apex, 4-10 mm long, straight, very delicate and flexuous; plant an annual, flowering April-June ...............................................A. elliottiana 5 Lemma awned or not, the awn (when present) inserted either near the middle of the lemma or near the apex, 0-6 mm long, straight or bent, neither delicate nor flexuous; plant a perennial, flowering (collectively) March-November. 6 Lemma with a 3-6 mm long, geniculate awn inserted near the middle; [plants of high elevation rock outcrops] . ............................................................................... A. mertensii 6 Lemma awnless or with a 0-3 mm long, straight awn inserted near the tip; [plants of various habitats]. 7 Spikelets 1.2-2 mm long; anthers 0.3-0.6 mm long; plants flowering March-July . A. hyemalis 7 Spikelets (1.8-) 2.2-3.5 (-3.7) mm long; anthers (collectively) 0.3-1.2 mm long; plants flowering June- November. 8 Leaves mostly involute, 1-2 (-3) mm wide; panicle branches mostly forking well beyond the middle . ......................................................................... A. scabra 8 Leaves flat, 2-6 mm wide; panicle branches mostly forking at or below the middle. 9 Lemma 1.8-3 mm long, minutely but copiously scabrous (at 20× or more); anthers 0.7-1.2 mm long; spikelets (2.3-) 2.7-3.5 (-3.7) mm long, usually clustered near the tips of the branchlets; panicle branches scabrous; culms to 15 dm tall; [plants of wet savannas and other wet habitats of the Coastal Plain] ........................................................ A. altissima 9 Lemma 1.4-2 mm long, glabrous; anthers 0.3-0.6 mm long; spikelets (1.8-) 2.2-2.7 (-3.2) mm long, usually not clustered near the tips of the branchlets; panicle branches glabrous to scabrous; culms to 10 dm tall; [plants of various habitats, nearly throughout our area] . A. perennans Agrostis altissima (Walter) Tuckerman, Coastal Bog Bentgrass. Cp (NC, SC, VA), Mt (VA): wet savannas, sinkhole ponds, edges of swamp forests; rare (NC Watch List, VA Watch List). October-November. MA (?) and NJ south to se. LA, primarily on the Coastal Plain. [= F, HC, Z; A. perennans -- RAB, GW, K, in part; A. perennans var. elata (Pursh) A. Hitchcock -- C, G, S] * Agrostis capillaris Linnaeus, Rhode Island Bentgrass, Colonial Bentgrass. Mt (NC, VA), Pd, Cp (VA): meadows, roadsides, disturbed areas; uncommon, introduced from Europe (and possibly n. North America). June-August. [= C, K, Z; A. tenuis Sibthorp -- RAB, G, HC, S, W; A. tenuis var. tenuis -- F] Agrostis elliottiana J.A. Schultes, Elliott's Bentgrass, Southern Bentgrass. Pd, Cp (NC, SC, VA), Mt (NC): dry soils of barrens, fields, and rock outcrops; uncommon (VA Watch List). April-June. MD west to OH, KS, and KS, south to FL and TX. [= RAB, C, F, G, HC, K, S, W, Z] * Agrostis gigantea Roth, Redtop, Black Bentgrass. June-October. (SC, VA). [= C, F, K, W, Z; A. stolonifera -- RAB, GW, in part, misapplied; A. stolonifera Linnaeus var. major (Gaudin) Farwell -- G; A. alba -- HC, misapplied; A. alba -- S, in part, misapplied] Agrostis hyemalis (Walter) Britton, Sterns, & Poggenberg, Ticklegrass, Small Bentgrass. (NC, SC, VA).