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No key was found for the requested taxon, but it is the only child of Microstegium. Showing where it is keyed below.

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Key to Poaceae, Key E: grasses of tribe Andropogoneae (also including grasses also keyed in Keys B, C, and D)

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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; [exotic weeds].
..2 Leaves cordate-clasping at base; spikelets not paired, unaccompanied by a vestige
..2 Leaves tapering to a broadly cuneate base; spikelets paired (one of the pair sometimes vestigial)
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
........5 Internode broader than and more-or-less enclosing the female spikelet.
..........6 Racemes of mixed sex, female flowers below, and male above
..........6 Racemes of single sex, the female inflorescences (“ears”) borne on axillary branches, the male inflorescences (“tassels”) terminal on the culm
 Zea
......4 Spikelets, or at least one of each pair, bisexual.
............ 7 Culms 2-45 cm tall; leaves 1-5 mm wide; plants perennial, obviously and prominently rhizomatous; lower glume with pectinate margins; [commonly naturalized turf grass and roadside weed]
............ 7 Culms 30-400 cm tall; leaves 2-25 mm wide; plants annual or perennial, cespitose or short-rhizomatous; lower glume winged or not, but not pectinate.
............ ..8 Lower glumes of the sessile spikelets rough, rugose, pitted, tuberculate or alveolate between the keels
............ ..8 Lower glumes of the sessile spikelets smooth or scabrous.
............ ....9 Pedicels at least partially fused to the rame axes
............ ....9 Pedicels appressed, but not fused, to the rame axes
....3 Spikelets not embedded or fitting into grooves in the rachis, the rachis slender (the spikelets visibly separate and often pedicelled).
............ ........11 Pedicelled spikelet similar to the sessile spikelet, both fertile.
............ ..........12 Spikelets falling separately from the persistent rachis.
............ ..........12 Spikelets falling in pairs together with sections of the disarticulating rachis.
............ ............ ..14 Spikelets awned with awns 10-26 mm long; anthers 2; [native, collectively common and widespread]
............ ............ ..14 Spikelets unawned or with awns to 5.2 mm long; anthers 3; [exotic, rarely encountered]
............ ............ ....15 Spikelets with awns 4-5.2 mm long
............ ........11 Pedicelled spikelet differing from the sessile in shape and sex (sometimes represented only by a pedicel).
............ ............ ......16 Spikelets awned, the awn 10-20 cm long.
............ ............ ........17 First glume lacking glands; panicle open, the branches 5-8 cm long
............ ............ ......16 Spikelets with or without awns, if awned the awns < 5 cm long.
............ ............ ..........18 Inflorescence a panicle, the branches not subtended by sheaths.
............ ............ ............ 19 Pedicelled spikelet represented by pedicel only; apex of sheath bearing 2 auricles 1-10 mm long; [native]
............ ............ ..........18 Inflorescence of 1-13 digitate (whorled) racemes borne at the summit of a peduncle, the peduncle subtended by a raceme sheath.
............ ............ ............ ....21 Pedicels of the pedicelled (reduced or absent) spikelets terete or slightly flattened and grooved on one side only
............ ............ ............ ....21 Pedicels of the pedicelled (reduced or absent) spikelets strongly flattened and with or without grooves on both sides.
............ ............ ............ ......22 Rame internodes and pedicels with a translucent medial groove; pedicelled spikelets smaller than the sessile spikelets (or vestigial/absent)
............ ............ ............ ......22 Rame internodes and pedicels without a translucent medial groove; pedicelled spikelets ca. the same size as sessile spikelets
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