Poa autumnalis

Muhl. ex Elliott
Common names: Autumn bluegrass
Endemic
Treatment appears in FNA Volume 24. Treatment on page 514.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Plants perennial; not rhizomatous, not stoloniferous, loosely tufted. Basal branching mainly pseudointravaginal. Culms 23-86 cm tall, 0.8-1.8 mm thick, bases often decumbent. 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. 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. Spikelets 3-8.2 mm, laterally compressed; florets 2-4 (6); rachilla internodes smooth, sparsely softly puberulent. 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. 2n = 28.

Distribution

Md., N.J., Okla., Miss., Tex., La., Pa., Del., Mich., Ala., D.C., Tenn., N.C., S.C., Va., Ark., Greenland, Nunavut, Que., Ill., Ga., Ind., Ky., Fla.

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.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Poa autumnalis"
membranous +  and scarious +
puberulent +, hispidulous +, hairy +  and glabrous +
2.6 cm26 mm <br />0.026 m <br /> (?) +
0.1 cm1 mm <br />0.001 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
scarious-hyaline +
Blunt (?) +  and Obtuse (?) +
Robert J. Soreng +
Muhl. ex Elliott +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
keeled +  and rounded +
strigose +  and glabrous +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
not evident +
glabrous +, scabrous +  and smooth +
folded +  and flat +
thin;1mm;4mm +
spreading;reflexed +
hispidulous +, glabrous +, smooth or +  and sparsely densely scabrous +
webbed +  and glabrous +
compressed +  and terete +
Autumn bluegrass +
unbranched +  and hollow +
23 cm230 mm <br />0.23 m <br /> (86 cm860 mm <br />0.86 m <br />) +
ascending +  and erect +
compressed +  and terete +
20 cm200 mm <br />0.2 m <br /> (126 cm1,260 mm <br />1.26 m <br />) +
not woody +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
Md. +, N.J. +, Okla. +, Miss. +, Tex. +, La. +, Pa. +, Del. +, Mich. +, Ala. +, D.C. +, Tenn. +, N.C. +, S.C. +, Va. +, Ark. +, Greenland +, Nunavut +, Que. +, Ill. +, Ga. +, Ind. +, Ky. +  and Fla. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
2 +  and 4 +
compressed +
reduced +
1-3(5)-veined +
shorter or longer +
subtending +
unequal +
distributed +
uncinate +
0.1 cm1 mm <br />0.001 m <br /> (?) +
0 +  and 1/6 +
Oval (?) +  and Round (?) +
milky white +  and slightly greenish +
long-villous +
5(7-11)-veined +
hairy +  and glabrous +
keeled +  and lanceolate +
0.3 cm3 mm <br />0.003 m <br /> (0.46 cm4.6 mm <br />0.0046 m <br />) +
membranous +
erose +  and entire +
white +  and milky white or hyaline +
ciliolate +  and smooth +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.19 cm1.9 mm <br />0.0019 m <br />) +
membranous +
inconspicuous +
lobed +  and lanceolate +
subulate +  and lanceolate +
white +  and clear +
glabrous +, scabrous +  and smooth +
concealed +  and prominent +
0 +  and 5 +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
5 cm50 mm <br />0.05 m <br /> (?) +
pyramidal +
8 cm80 mm <br />0.08 m <br /> (20 cm200 mm <br />0.2 m <br />) +
dry +  and fleshy +
keeled +  and terete +
compressed +
0.3 cm3 mm <br />0.003 m <br /> (0.82 cm8.2 mm <br />0.0082 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Poa autumnalis +
Poa sect. Sylvestres +
species +
membranous +
lanceolate +  and broadly lanceolate +
parallel +  and converging +
branching +, not stoloniferous +  and not rhizomatous +
aquatic +  and terrestrial +