Poa bulbosa |
Poa trivialis |
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bulbous blue grass |
rough blue grass, rough-sheath blue grass, rough-stalk blue grass |
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Habit | Plants perennial; densely tufted, not rhizomatous, not stoloniferous. | Plants perennial, short-lived; somewhat loosely to densely tufted, usually weakly stoloniferous. | ||||
Culms | 15-60 cm, erect or spreading, bases bulbous. |
25-120 cm, decumbent to erect, sometimes trailing and rooting at the nodes, terete or weakly compressed; nodes terete or slightly compressed, (0)1-3 exserted. |
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Sheaths | closed for about 1/4 their length, terete, lowest sheaths with swollen bases; ligules 1-3 mm, smooth or scabrous, apices obtuse to acute; blades 1-2.5 mm wide, flat, thin, lax, soon withering. |
closed for about 1/3-1/2 their length, compressed, usually densely scabrous, bases of basal sheaths glabrous, distal sheath lengths 0.5-4 times blade lengths; collars smooth or scabrous, glabrous; ligules 3-10 mm, scabrous, acute to acuminate; blades 1-5 mm wide, flat, lax, soft, sparsely scabrous over the veins, margins scabrous, apices narrowly prow-shaped. |
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Basal branching | intravaginal. |
intra-vaginal. |
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Panicles | 3-12 cm, ovoid; nodes with 2-5 branches; branches ascending to spreading, terete, usually smooth or sparsely scabrous, infrequently moderately scabrous. |
8-25 cm, erect or lax, pyramidal, open, with 35-100+ spikelets; nodes with 3-7 branches; branches 2-8(10) cm, ascending to spreading, flexuous to fairly straight, angled, angles densely scabrous, crowded, with 5-35 spikelets in the distal 1/2-3/4. |
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Spikelets | 3-5 mm, laterally compressed, usually bulbiferous; florets 3-7, the basal floret, and sometimes additional florets, normal; rachilla internodes smooth, glabrous. |
2.3-3.5 mm, lengths to 3 times widths, laterally compressed; florets 2-4, bisexual; rachilla internodes smooth or muriculate. |
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Glumes | keeled, keels scabrous; lower glumes 3-veined; upper glumes shorter than or subequal to the lowest lemmas; calluses webbed or glabrous; lemmas 3-4 mm, lanceolate, keeled, glabrous or the keels and marginal veins short- to long-villous, intercostal regions glabrous or softly puberulent, apices acute; paleas scabrous, keels often softly puberulent at midlength; anthers 1.2-1.5 mm and functional, sometimes aborted late in development, sometimes not developed. |
distinctly keeled, keels scabrous; lower glumes subulate to narrowly lanceolate, usually arched to sickle-shaped, 1-veined, distinctly shorter than the lowest lemmas; calluses webbed, hairs over 2/3 the lemma length; lemmas 2.3-3.5 mm, lanceolate, distinctly keeled, keels usually sparsely puberulent to 3/5 their length, marginal veins usually glabrous, infrequently the proximal 1/4 softly puberulent, intercostal regions smooth, glabrous, upper lemmas sometimes glabrous, lateral veins prominent, margins glabrous, apices acute; palea keels smooth, muriculate, tuberculate, or minutely scabrous; anthers 1.3-2 mm. |
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2n | = 14, 21, 28, 39, 42, 45. |
= 14. |
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Poa bulbosa |
Poa trivialis |
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Distribution |
AR; AZ; CA; CO; CT; DE; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; MI; MN; MO; MT; NC; ND; NE; NJ; NM; NV; NY; OH; OK; OR; PA; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY
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AK; AL; CA; CO; CT; DC; DE; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MT; NC; NE; NH; NJ; NM; NV; NY; OH; OR; PA; RI; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; BC; LB; NB; NS; ON; PE; QC; SK; YT; Greenland
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Discussion | Poa bulbosa is a European species that is now established in the Flora region. In southern Europe and the Middle East, it is considered an important early spring forage. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Poa trivialis is an introduced European species. Only Poa trivialis subsp. trivialis is present in the Flora region. Several cultivars have been planted for pastures and lawns, and have often escaped cultivation. Poa trivialis sometimes grows with P. paludigena (p. 572), but has distinctly longer ligules and anthers. It is easily recognized by its flat blades, long ligules, sickle-shaped lower glumes, prominent callus webs, and lemmas with pubescent keels and pronounced lateral veins. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 24, p. 516. | FNA vol. 24, p. 568. | ||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Arenariae | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Pandemos | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | L. | L. | ||||
Web links |
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