Poa cusickii |
Poa secunda |
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Cusick's bluegrass |
big bluegrass, curly blue grass, Nevada blue grass, Nevada bluegrass (ssp. juncifolia), pine bluegrass, Sandberg bluegrass, Sandberg's bluegrass, secund bluegrass |
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Habit | Plants perennial; usually densely tufted, rarely moderately densely tufted, usually neither rhizomatous nor stoloniferous, infrequently short-rhizomatous or stoloniferous, rarely with distinct rhizomes. | Plants perennial; frequently anthocyanic, sometimes glaucous; densely tufted, basal leaf tufts 2-20+ cm, usually narrowly based, rarely with rhizomes. | ||||||||||||||||
Culms | 10-60(70) cm tall, 0.5-1.8 mm thick, erect or the bases decumbent, terete or weakly compressed; nodes terete, 0-2 exserted. |
(10)15-120 cm, slender to stout, erect or the bases slightly decumbent, terete or weakly compressed; nodes terete, 0-2 exserted. |
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Sheaths | closed for 1/4-3/4 their length, terete, smooth or scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths 1.6-10 times blade lengths; collars smooth or scabrous, glabrous; ligules of cauline leaves 1-3(6) mm, smooth or scabrous, truncate to acute, ligules of the innovation leaves 0.2-0.5(2.5) mm, scabrous, usually truncate; innovation blades sometimes distinctly different from the cauline blades, 0.5-2 mm wide, involute, moderately thick, moderately firm, adaxial surfaces usually densely scabrous or hispidulous to softly puberulent, infrequently nearly smooth and glabrous; cauline blades subequal or the midcauline blades longest or the blades gradually reduced in length distally, 0.5-3 mm wide, flat, folded, or involute, usually thin, usually withering, abaxial surfaces smooth or scabrous, apices narrowly to broadly prow-shaped, flag leaf blades 0.5-5(6) cm. |
closed for 1/10-1/4 their length, terete, smooth or scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths (0.95)1.5-7(15) times blade lengths; collars smooth or scabrous, glabrous; ligules 0.5-6(10) mm, smooth or scabrous, truncate to acuminate, ligules of innovation leaves similar to those of the cauline leaves or shorter and truncate; innovation blades similar to the cauline blades; cauline blades gradually reduced in length upwards or the middle blades longest, 0.4-3(5) mm wide, flat, folded, or involute, thin, soft, and soon withering to thick, firm, and persisting, smooth or scabrous mainly over the veins, glabrous, apices narrowly prow-shaped, flag leaf blades 0.8-10(17) cm. |
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Basal branching | intravaginal or intra- and extravaginal. |
intra- and extra vaginal. |
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Panicles | 2-10(12) cm, usually erect, contracted or loosely contracted, narrowly lanceoloid to ovoid, congested or moderately congested, with 10-100 spikelets and 1-3(5) branches per node; branches 0.5-4(5) cm, erect or steeply ascending, fairly straight, slender to stout, terete to angled, smooth or scabrous, with 1-15 spikelets. |
2-25(30) cm, erect or somewhat lax, narrowly lanceoloid to ovoid, usually contracted, more or less open at anthesis, infrequently remaining open at maturity, green or anthocyanic, sometimes glaucous, usually moderately congested, with 10-100+ spikelets; nodes usually with 1-3 branches; branches (0.5)1-8(10) cm, usually erect or ascending, infrequently spreading at maturity, terete to weakly angled, usually sparsely to densely scabrous on and between the angles, with (1)2-20(60+) spikelets in the distal 1/2-1/3. |
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Spikelets | (3)4-10 mm, lengths to 3 times widths, broadly lanceolate to narrowly ovate, laterally compressed, not sexually dimorphic; florets 2-6; rachilla internodes 0.5-1.2 mm, smooth or scabrous. |
(4)5-10 mm, lengths (3.8)4-5 times widths, usually narrowly lanceolate, subterete to weakly laterally compressed, drab, green or strongly anthocyanic, sometimes glaucous; florets (2)3-5(10); rachilla internodes usually 1-2 mm, terete or slightly dorsally compressed, smooth or muriculate to scabrous. |
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Glumes | lanceolate, distinctly keeled; lower glumes 3-veined, distinctly shorter than the lowest lemmas; calluses glabrous or diffusely webbed, hairs less than 1/4 the lemma length; lemmas (3)4-7 mm, lanceolate to broadly lanceolate, distinctly keeled, membranous to thinly membranous, smooth or sparsely to densely scabrous, glabrous or the keels and/or marginal veins puberulent proximally, lateral veins obscure to prominent, margins glabrous, apices acute; palea keels scabrous, intercostal regions glabrous; anthers vestigial (0.1-0.2 mm), aborted late in development, or 2-3.5 mm. |
broadly lanceolate, keels indistinct; lower glumes 3-veined; calluses glabrous or with a crown of hairs, hairs 0.1-0.5(2) mm, crisp or slightly sinuous; lemmas 3.5-6 mm, lanceolate to narrowly lanceolate or slightly oblanceolate, usually weakly keeled, glabrous or the keels and marginal veins softly puberulent to short-villous, intercostal regions smooth or scabrous, glabrous, short-villous, crisply puberulent or softly puberulent over the basal 2/3, hairs usually 0.1-0.5 mm, hairs of the keels and veins frequently similar in length to those between the veins, usually not or only slightly denser and extending further towards the apices, lateral veins obscure, margins strongly inrolled below, broadly scarious above, glabrous, apices obtuse to broadly acute, blunt, or pointed; palea keels scabrous, glabrous or softly puberulent to short-villous at midlength; anthers 1.5-3 mm. |
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2n | = 28, 28+11, 56, 56+11, 59, ca. 70. |
= 42, 44+f, ca. 48, 56, ca. 62, 63, ca. 66, ca. 68, 70, ca.72, ca. 74, 78, ca. 80, 81, 82, ca. 83, 84-86, ca. 87, ca. 88, ca. 90, ca. 91, 93, ca. 94, ca. 97, ca. 98, ca. 99, 100, 104, 105-106. |
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Poa cusickii |
Poa secunda |
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Distribution |
CA; CO; ID; MT; ND; NV; OR; UT; WA; WY; AB; BC; MB; SK; YT
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AK; AZ; CA; CO; ID; ME; MI; MN; MT; ND; NE; NM; NV; OK; OR; SD; UT; WA; WY; AB; BC; NT; ON; QC; SK; YT
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Discussion | Poa cusickii grows in rich meadows in sagebrush scrub to rocky alpine slopes, from the southwestern Yukon Territory to Manitoba and North Dakota, south to central California and eastern Colorado. It is gynodioecious or dioecious. Sexually reproducing plants of Poa cusickii subspp. cusickii and pallida grow in different geographic areas, but pistillate plants of these two subspecies have overlapping ranges. Only pistillate plants are known in Poa cusickii subspp. epilis and purpurascens. All the alpine plants studied were pistillate. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Poa secunda is one of the major spring forage species of temperate western North America. It is very common in high deserts, mountain grasslands, saline wetlands, meadows, dry forests, and on lower alpine slopes, primarily from the Yukon Territory east to Manitoba and south to Baja California, Mexico. It also extends sporadically eastward across the Great Plains to the Gaspe Peninsula, Quebec. Both subspecies are present, as disjuncts, in Patagonia. Poa secunda is highly variable. Hitchcock (1951) divided it into two groups, with a total of seven species. The two groups are recognized here as subspecies. They overlap almost completely in terms of morphology, but differ ecologically and cytologically. Poa secunda is known or suspected to hybridize with several other species, including P. arctica (p. 529), P. arida (p. 599), P. glauca (p. 576), and P. pratensis (p. 522). Plants from the Columbia River Gorge in Oregon, including the type of P. multnomae Piper, that approach P. tenerrima (p. 588) are presumed to be derived from hybridization between P. secunda and P. nervosa (p. 545). Poa secunda differs from P. curtifolia (p. 589), with which it is sometimes confused, in having longer leaf blades that are sometimes folded or involute, and more spikelets per branch. Apomixis is common and facultative. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 24, p. 559. | FNA vol. 24, p. 586. | ||||||||||||||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Epiles | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Secundae > subsect. Secundae | ||||||||||||||||
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Synonyms | P. canbyi, P. buckleyana | |||||||||||||||||
Name authority | Vasey | J. Presl | ||||||||||||||||
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