Poa cuspidata |
Poa nemoralis |
|
---|---|---|
early bluegrass |
Eurasian woodland bluegrass, forest blue grass, interior bluegrass (ssp. interior), wood blue grass, woodland bluegrass, woods bluegrass (ssp. nemoralis) |
|
Habit | Plants perennial; loosely tufted or with solitary shoots, shortly rhizomatous. | Plants perennial; green or glaucous; densely tufted, not stoloniferous, not rhizomatous. |
Culms | 15-60 cm, erect or the bases decumbent, not branching above the base, terete or weakly compressed; nodes terete, 0-1 exserted. |
30-80 cm, mostly erect, smooth below the panicles; nodes slightly compressed, 2-5 exserted, top node at 1/2 - 3/4 the culm length. |
Sheaths | closed for about 1/2 their length, slightly compressed, distinctly keeled, glabrous, bases of basal sheaths glabrous, distal sheath lengths 4-60 times blade lengths; collars of proximal leaves usually retrorsely scabrous or pubescent distally and about the throat; ligules 0.5-4 mm, smooth or scabrous, apices truncate to acute; innovation blades similar to the cauline blades; cauline blades 1-4 mm wide, usually flat, sometimes slightly folded, smooth or sparsely scabrous, primarily over the veins, apices broadly prow-shaped, blades steeply reduced in length distally, flag leaf blades 0.2-3(6) cm. |
closed for 1/10 – 1/5 their length, terete, bases of basal sheaths glabrous, distal sheath lengths 0.45-1 (1.1) times blade lengths; ligules 0.2-0.8(1) mm, sparsely to densely scabrous, apices truncate, minutely ciliolate; blades 0.8-3 mm wide, mostly flat, appressed, abruptly ascending to spreading, straight or somewhat lax, apices narrowly prow-shaped. |
Basal branching | mainly extravaginal. |
all or mostly extravaginal. |
Panicles | 5-15 cm, erect or lax, pyramidal, open, sparse, with 20-80 spikelets, proximal internodes usually 3+ cm; nodes usually with 2 branches; branches (2)3-7(10) cm, spreading to reflexed, straight, angled, angles scabrous, with 2-8(10) spikelets. |
7-16(20) cm, lengths usually 2.5-4 times widths at maturity, usually erect, lax in shade forms, narrowly lanceoloid to ovoid, slightly to moderately congested; nodes with 2-5 branches; branches ascending to widely spreading, fairly straight, slender to moderately stout, angled, angles moderately to densely scabrous. |
Spikelets | 5-8 mm, lengths to 3.5 times widths, laterally compressed, not sexually dimorphic; florets 2-5; rachilla internodes smooth. |
3-8 mm, lengths 2.5-3.5 times widths, narrowly lanceolate to lanceolate, laterally compressed, usually not glaucous; florets (1)2-5; rachilla internodes usually shorter than 1 mm, smooth, muriculate, or scabrous, usually puberulent, infrequently hispidulous or glabrous. |
Glumes | narrowly lanceolate to lanceolate, distinctly keeled; lower glumes 1-3-veined; calluses webbed, hairs over 1/3 the lemma length; lemmas 3-6 mm, lanceolate, distinctly keeled, keels and marginal veins sparsely short- to long-villous, lateral veins moderately prominent, intercostal regions glabrous or the upper florets in the spikelets softly puberulent, margins glabrous, apices acute; palea keels scabrous, softly puberulent at midlength; anthers vestigial (0.1-0.2 mm) or 2-3.5 mm. |
subulate to narrowly lanceolate, distinctly keeled, keels smooth or sparsely scabrous, apices sharply acute to acuminate; lower glumes 3-veined, long-tapered to a slender point, lengths 6.4-11 times widths; upper glumes shorter than or subequal to the lowest lemmas; calluses webbed, hairs sparse, often short; lemmas 2.4-4 mm, proximal lemma widths less than 1/5 times lengths, narrowly lanceolate to lanceolate, distinctly keeled, keels and marginal veins short-villous, lateral veins glabrous, obscure, intercostal regions smooth or muriculate, glabrous, margins glabrous, apices acute, usually partially bronze-colored; palea keels scabrous, intercostal regions glabrous; anthers 0.8-1.9 mm. |
2n | = 28. |
= 28, 35, 42, 48, 50, 56. |
Poa cuspidata |
Poa nemoralis |
|
Distribution |
AL; DC; DE; GA; IN; KY; LA; MD; NC; NJ; NY; OH; PA; SC; TN; VA; WV
|
AK; AZ; CA; CO; CT; DE; IA; ID; IL; IN; KY; MA; MD; ME; MI; MN; MO; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OR; PA; RI; SD; TN; TX; UT; VA; VT; WA; WI; WY; AB; BC; MB; NB; NL; NS; NT; ON; QC; SK; YT; Greenland
|
Discussion | Poa cuspidata is a common species of forest openings in the Appalachian Mountains. It is an eastern counterpart of P. arnowiae (see previous), P. tracyi (p. 543), and P. nervosa (see next). Like those species, it is sequentially gynomonoecious. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Introduced from northern Eurasia, Poa nemoralis is established primarily at low elevations in deciduous and mixed conifer/deciduous forests. It is now common in southeastern Canada and the northeastern United States, and is spreading in the west. It can be distinguished from P. glauca (p. 576) and P. interior (see next) by its consistently short ligules, high top culm node, relatively long flag leaf blades, and narrow glumes and lemmas. It is usually hexaploid. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 545. | FNA vol. 24, p. 574. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Poa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Stenopoa |
Sibling taxa | ||
Name authority | Nutt. | L. |
Web links |
|