Phleum alpinum |
Poaceae subfam. pooideae |
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alpine timothy, fléole alpine, mountain timothy, phléole alpine, timothy grass |
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Habit | Plants perennial; cespitose, sometimes shortly rhizomatous. | Plants annual or perennial; sometimes matlike, sometimes cespitose, sometimes stoloniferous, sometimes rhizomatous. | ||||||||||||||||||||||||||||||||||||
Culms | 15-50 cm, often decumbent, lower internodes not enlarged or bulbous. |
usually hollow, sometimes solid. |
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Sheaths | of the flag leaves inflated; auricles not developed, leaf edges sometimes wrinkled at the junction of the sheath and blade; ligules 1-4 mm, truncate; blades to 17 cm long, 4-7 mm wide, flat. |
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Leaves | distichous; sheaths usually open to the base, varying to closed for nearly their full length; auricles present or absent; abaxial ligules absent; adaxial ligules scarious or membranous, sometimes puberulent or scabridulous, usually not ciliate, cilia sometimes shorter than the base; pseudopetioles rarely present; blades usually linear, sometimes broadly so, venation parallel; cross sections non-Kranz, mesophyll nonradiate, adaxial palisade layer absent, fusoid and arm cells usually absent; midribs usually simple; adaxial bulliform cells present; stomates with parallel-sided subsidiary cells; epidermes usually lacking bicellular microhairs, sometimes with unicellular microhairs, papillae usually absent, when present, rarely more than 1 per cell. |
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Panicles | 1-6 cm long, 5-12 mm wide, usually 1.5-3 times as long as wide, subglobose to broadly cylindric, not tapering distally; branches adnate to the rachises. |
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Inflorescences | usually terminal, panicles, spikes, or racemes, usually ebracteate; disarticulation usually below the florets, sometimes below the glumes, at the rachis nodes, or at the inflorescence bases. |
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Spikelets | usually bisexual, infrequently unisexual or mixed, usually laterally compressed or not compressed, occasionally dorsally compressed, with 1-30 sexual florets, distal floret(s) often reduced, infrequently spikelets with 1-2 reduced or staminate basal florets and a single terminal sexual floret. |
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Glumes | 2.5-4.5 mm, sides scabrous, keels hispid, apices awned, awns 0.8-2.5(3.2) mm; lemmas 1.7-2.5 mm, about 3/4 as long as the glumes, mostly glabrous, keels hairy, hairs to 0.1 mm; anthers 1-1.5(2) mm. |
usually 2, upper or lower glumes sometimes absent, rarely both glumes absent; lemmas without uncinate hairs, awned or not, awns single, basal to apical; paleas usually well-developed, sometimes reduced or absent; lodicules 2(3), usually lanceolate and broadly membranous distally, rarely truncate and fleshy, usually not veined or obscurely veined, sometimes distinctly veined, sometimes ciliate; anthers (1, 2)3; ovaries glabrous or sometimes hairy distally, sometimes with an apical appendage; haustorial synergids absent; styles (1)2 (-4), bases close together, sometimes fused. |
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Caryopses | hila linear, elliptic, ovate, or punctate; endosperm usually hard, sometimes soft or liquid, with or without lipids, starch grains compound or simple; embryos less than 1/2 the length of the caryopses; epiblasts usually present; scutellar cleft usually absent; mesocotyl internode usually absent; embryonic leaf margins overlapping, x = 7, 10. |
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2n | = 14, 28. |
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Phleum alpinum |
Poaceae subfam. pooideae |
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Distribution |
AK; AZ; CA; CO; ID; ME; MI; MT; NH; NM; NV; OR; SD; UT; WA; WY; AB; BC; NB; NL; NS; NT; ON; QC; SK; YT; Greenland
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Discussion | Phleum alpinum grows along stream banks, on moist prairie hillsides, and in wet mountain meadows. It is a circumboreal species extending, in the Flora region, from northern North America southward through the mountains to Mexico and South America. It is also widespread in northern Eurasia. Isolated, depauperate plants of P. pratense may be difficult to distinguish from P. alpinum; there is never any difficulty in the field. Kula et al. (2006) demonstrated that American and northern European plants of Phleum alpinum belong to the same taxon. They mistakenly identified the taxon as P. commutatum Gaudin. Because Humphries (1978) lectotypified P. alpinum on a plant from Lapland, it has priority over P. commutatum. North American plants belong to P. alpinum L. subsp. alpinum and are tetraploid. The count of 2n =14 applies to Phleum alpinum subsp. rhaeticum Humphries, which grows in the mountains of central and southern Europe. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 24, p. 672. | FNA vol. 24, p. 57. | ||||||||||||||||||||||||||||||||||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Phleum | Poaceae | ||||||||||||||||||||||||||||||||||||
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Synonyms | P. commutatum var. americanum, P. commutatum, P. alpinum var. commutatum, P. alpinum subsp. commutatum | |||||||||||||||||||||||||||||||||||||
Name authority | L. | Benth. | ||||||||||||||||||||||||||||||||||||
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