Poaceae subfam. Pooideae
The subfamily Pooideae includes approximately 3300 species, making it the largest subfamily in the Poaceae. It reaches its greatest diversity in cool temperate and boreal regions, extending across the tropics only in high mountains.
The circumscription and relationships of tribes within the Pooideae are unsettled (see, for example, Catalan et al. 1997, 2004; Soreng and Davis 1998). In this flora, some previously recognized tribes have been combined with the Poeae. Recognition of some of these as subtribes is well supported; among these is the Hainardieae Greuter (which, at the subtribal level, is called the Parapholiinae Caro). Members of other traditional tribal groupings, such as the Aveneae Dumort., appear to be widely dispersed within the Poeae sensu lato. Further work will probably support the division of the expanded Poeae into additional tribes; there is as yet no clear indication as to what the boundaries of such tribes should be.
Catalan, P., P. Torrecilla, J.A.L. Rodriguez, and R.G. Olmstead. 2004. Phylogeny of the festucoid grasses of subtribe Loliinae and allies (Poeae, Pooideae) inferred from ITS and trnL-V sequences. Molecular Phylogenetics and Evolution 31:517-541.
|1||Inflorescences 1-sided spikes, the spikelets radial to and partially embedded in the rachises; spikelets with 1 floret each||Nardeae|
|1||Inflorescences panicles, racemes, or 2-sided spikes with spikelets radial or tangential to the rachises, sometimes embedded in the axes, never both radial and embedded; spikelets with 1-30 florets.||> 2|
|2||Cauline leaf sheaths closed for at least 3/4 their length; lemmas longer than (4.5)6.5 mm or awned or with prominent, parallel veins.||> 3|
|3||Ovary apices glabrous; styles fused at the base, divergent, naked on the lower portion, plumose distally; lemmas often with a purplish band in the distal 1/2, usually unawned; distal 1-3 florets often reduced to lemmas, the lower 1-2 lemmas often enclosing the terminal lemmas; lodicules about 0.2-0.5 mm long, truncate, fleshy, without a distal membranous portion||Meliceae|
|3||Ovary apices hairy; styles separate and plumose to the base; lemmas usually without a purplish band, sometimes with purplish bases, usually awned; distal 1-2 florets sometimes reduced, each separate with lemma and palea; lodicules usually more than 1 mm long, fleshy at the base, with a distal membranous portion||Bromeae|
|2||Cauline leaf sheaths usually open for most or all of their length; if the sheaths closed, the lemmas shorter than 7 mm, unawned and with lemma veins inconspicuous and converging distally.||> 3|
|4||Inflorescences usually spikes or spikelike racemes, sometimes panicles, lateral spikelets on pedicels less than 3 mm long; if inflorescences with 1 spikelet per node, the spikelets tangential to the rachises or pedicellate and the lemmas unawned or terminally awned; ovary apices hairy.||> 5|
|5||Glumes unequal, exceeded by the lowest lemmas, lanceolate, apices obtuse to acuminate or mucronate, rarely awned; inflorescences spikelike racemes, all spikelets pedicellate; pedicels 0.5-2.5 mm long||Brachypodieae|
|5||Glumes equal to unequal, sometimes absent, frequently exceeding the lowest lemmas, subulate to lanceolate, ovate, or obovate, apices truncate to acuminate, frequently awned; inflorescences usually spikes or spikelike, with 1 or more sessile spikelets per node, sometimes a panicle; pedicels absent or up to 4 mm long||Triticeae|
|4||Inflorescences usually panicles, sometimes racemes with pedicels more than 2.5 mm long, or spikes with 1 spikelet per node and the spikelets radial or tangential to the rachises; if spikelets 1 per node and tangential, the lemmas awned from midlength to subapically, never terminally, if spikes with radial spikelets, the lemmas unawned or awned, awns basal to terminal; ovary apices usually glabrous, sometimes hairy.||> 5|
|6||Lower glumes absent or highly reduced; inflorescences panicles||Brachyelytreae|
|6||Lower glumes usually well-developed, sometimes present only on the terminal spikelets; inflorescences panicles, racemes, or spikes.||> 7|
|7||Caryopses beaked; blades tapering both basally and apically, midveins usually eccentric||Diarrheneae|
|7||Caryopses not beaked; blades usually tapering only apically, midveins usually centric.||> 8|
|8||Spikelets with 1 floret; lemmas terminally awned, the junction of the lemma and awn abrupt, evident; glumes equal to or longer than the florets||Stipeae|
|8||Spikelets with 1-22 florets; lemmas unawned or dorsally to terminally awned, if terminally awned, the transition from lemma to awn gradual, not evident; glumes absent or shorter than to longer than the adjacent florets.||> 9|
|9||Lemmas membranous, bidentate or bifid; both surfaces of the leaf blades deeply ribbed; ovary apices hairy; culms with solid internodes; plants cultivated or established at a few locations||Stipeae|
|9||Lemmas hyaline to membranous, entire or minutely bidentate; leaf blades rarely deeply ribbed on both sides; ovary apices usually glabrous; culms usually with hollow internodes; plants mostly native or established throughout the Flora region, sometimes cultivated||Poeae|