Festuca occidentalis |
Poaceae subfam. pooideae |
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western fescue |
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Habit | Plants densely to loosely cespitose, without rhizomes. | Plants annual or perennial; sometimes matlike, sometimes cespitose, sometimes stoloniferous, sometimes rhizomatous. | ||||||||||||||||||||||||||||||||||||
Culms | (25)40-80(110) cm, glabrous, smooth. |
usually hollow, sometimes solid. |
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Sheaths | closed for much less than 1/2 their length, glabrous, somewhat persistent or slowly shredding into fibers; collars glabrous; ligules 0.1-0.4 mm, usually longer at the sides; blades all alike, 0.3-0.7 mm in diameter, conduplicate, abaxial surfaces smooth or scabridulous, veins (3)5, ribs 1-5; abaxial sclerenchyma in 5-7 narrow strands, about as wide as the adjacent veins; adaxial sclerenchyma absent. |
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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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Inflorescences | (5)10-20 cm, open, with 1-2 branches per node; branches 1-15 cm, lax, widely spreading to reflexed, lower branches usually reflexed at maturity, with 2+ spikelets. |
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 | 6-12 mm, with 3-6(7) florets. |
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 | exceeded by the upper florets, ovate to ovate-lanceolate, glabrous and smooth or slightly scabrous; lower glumes 2-5 mm; upper glumes 3-6 mm; lemmas (4)4.5-6.5(8) mm, ovate-lanceolate to attenuate, glabrous or finely puberulent, awns 3-12 mm, usually longer than the lemma bodies; paleas slightly shorter than the lemmas, intercostal region scabrous or puberulent distally; anthers (1)1.5-2(3) mm; ovary apices densely pubescent. |
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 | = 28 [other numbers have been reported for this species, but are probably based on misidentifications]. |
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Festuca occidentalis |
Poaceae subfam. pooideae |
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Distribution |
AK; CA; ID; MI; MT; OR; SD; UT; WA; WI; WY; AB; BC; ON
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Discussion | Festuca occidentalis grows in dry to moist, open woodlands, forest openings, and rocky slopes, up to 3100 m. It extends from southern Alaska and northern British Columbia to southwestern Alberta, south to southern California and eastward to Wyoming, and, as a disjunct, around the upper Great Lakes in Ontario, eastern Wisconsin, and Michigan. It is sometimes important as a forage grass, but is usually not sufficiently abundant. (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. 437. | FNA vol. 24, p. 57. | ||||||||||||||||||||||||||||||||||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Festuca > subg. Festuca > sect. Festuca | Poaceae | ||||||||||||||||||||||||||||||||||||
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Name authority | Hook. | Benth. | ||||||||||||||||||||||||||||||||||||
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