Poa autumnalis |
Poa howellii |
|
---|---|---|
autumn bluegrass |
Howell's blue grass |
|
Habit | Plants perennial; not rhizomatous, not stoloniferous, loosely tufted. | Plants usually annual, rarely longer-lived; densely tufted, tuft bases narrow; not stoloniferous, not rhizomatous. |
Culms | 23-86 cm tall, 0.8-1.8 mm thick, bases often decumbent. |
(10) 25-80(120) cm tall, 0.4-1.75 mm thick, usually erect; nodes terete, usually 1-2 exserted. |
Sheaths | 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. |
closed for 1/2 - 7/8 their length, usually weakly compressed and keeled, usually scabrous, rarely smooth; ligules 1.5-5(10) mm, smooth or scabrous, acute; blades 1-7(10) mm wide, flat, lax, soft, finely scabrous, apices narrowly prow-shaped, cauline blades 2-10 cm. |
Basal branching | mainly pseudointravaginal. |
intravaginal. |
Panicles | (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. |
10-25(30) cm, erect, eventually open, with (1)3-5(7) branches per node; branches eventually spreading or reflexed, fairly straight, angled, angles usually moderately to densely scabrous, rarely sparsely scabrous. |
Spikelets | 3-8.2 mm, laterally compressed; florets 2-4(6); rachilla internodes smooth, sparsely softly puberulent. |
(2)4-6 mm, laterally compressed, with 2-5 florets; rachilla internodes about 1 mm, smooth, usually softly puberulent, infrequently glabrous. |
Glumes | 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. |
slightly unequal, lanceolate, distinctly keeled, keels and sometimes the lateral veins sparsely to moderately scabrous; lower glumes 1-3-veined; upper glumes shorter than or subequal to the lowest lemmas; calluses of some or all florets sparsely webbed; lemmas 2.5-3.5 mm, lanceolate to narrowly lanceolate, distinctly keeled, crisply puberulent proximally, hairs evenly distributed, finely scabrous distally, lateral veins obscure to prominent, margins narrowly hyaline, glabrous, apices narrowly acute, infrequently anthocyanic; palea keels sparsely scabrous, glabrous or softly puberulent at midlength, intercostal regions usually softly puberulent; anthers 3, 0.2-1 mm. |
2n | = 28. |
= unknown. |
Poa autumnalis |
Poa howellii |
|
Distribution |
AL; AR; DC; DE; FL; GA; IL; IN; KY; LA; MD; MI; MS; NC; NJ; OK; PA; SC; TN; TX; VA; NU; QC; Greenland
|
CA; OR; WA; BC
|
Discussion | 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.) |
Poa howellii grows primarily on rocky banks and wooded slopes, from the coastal ranges of southern British Columbia to southern California. It differs from P. bolanderi (see above) in having puberulent, rather than smooth or scabrous, lemmas, and in growing at lower elevations, mostly from near sea level to 1000 m. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 514. | FNA vol. 24, p. 534. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Sylvestres | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Homalopoa |
Sibling taxa | ||
Synonyms | P. bolanderi var. howellii | |
Name authority | Muhl. ex Elliott | Vasey & Scribn. |
Web links |
|