Poa nemoralis |
Poa autumnalis |
|
---|---|---|
Eurasian woodland bluegrass, forest blue grass, interior bluegrass (ssp. interior), wood blue grass, woodland bluegrass, woods bluegrass (ssp. nemoralis) |
autumn bluegrass |
|
Habit | Plants perennial; green or glaucous; densely tufted, not stoloniferous, not rhizomatous. | Plants perennial; not rhizomatous, not stoloniferous, loosely tufted. |
Culms | 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. |
23-86 cm tall, 0.8-1.8 mm thick, bases often decumbent. |
Sheaths | 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. |
closed for 1/3 – 1/2 their length; ligules 0.2-1.9(2.5) mm, smooth or obtuse; blades (0.5)1-4 mm wide, flat or folded, thin. |
Basal branching | all or mostly extravaginal. |
mainly pseudointravaginal. |
Panicles | 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. |
(5)8-20 cm, erect or lax, broadly pyramidal at maturity, open, sparse, lower axils sometimes sparsely pubescent; nodes with 1-2(4) branches; branches 5-12 cm, spreading to reflexed, straight, angled, angles scabrous, with 3-8 spikelets in the distal 1/4-1/3. |
Spikelets | 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. |
3-8.2 mm, laterally compressed; florets 2-4(6); rachilla internodes smooth, sparsely softly puberulent. |
Glumes | 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. |
distinctly shorter than the adjacent lemmas, distinctly keeled, keels scabrous; lower glumes subulate to lanceolate, (1)3-veined; upper glumes lanceolate to broadly lanceolate; calluses usually glabrous, rarely sparsely and shortly webbed; lemmas (2.8)3-4.6 mm, lanceolate, distinctly keeled, keels and marginal veins short- to long-villous, hairs extending up 3/4 of the keel, lateral veins prominent, intercostal regions softly puberulent, smooth, apices obtuse, blunt; palea keels softly puberulent to short-villous for much of their length, apices scabrous; anthers 1-1.4(2.6) mm. |
2n | = 28, 35, 42, 48, 50, 56. |
= 28. |
Poa nemoralis |
Poa autumnalis |
|
Distribution |
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
|
AL; AR; DC; DE; FL; GA; IL; IN; KY; LA; MD; MI; MS; NC; NJ; OK; PA; SC; TN; TX; VA; NU; QC; Greenland
|
Discussion | 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.) |
Poa autumnalis grows primarily in the southeastern United States, being found in forests of the eastern and western Appalachian piedmont and coastal plain. It is readily distinguished from other perennial species of the eastern United States by its combination of glabrous calluses and pubescent palea keels. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 574. | FNA vol. 24, p. 514. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Stenopoa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Sylvestres |
Sibling taxa | ||
Name authority | L. | Muhl. ex Elliott |
Web links |
|