Vegetative Morphology
Culms	30-120 cm, glabrous.
Ligules	0.2-1 mm.
Blades	4-10(20) cm long, (1)2-8 mm wide, flat to slightly involute.
Reproductive Morphology
Panicles	7-35 cm long, 2-10 cm wide, erect to nodding, with relatively few, loosely arranged spikelets.
Spikelets	4.5-9.5 mm.
Lower glumes	about 1/2 as wide as the upper glumes.
Upper glumes	3.6-6.2 mm, elliptical to oblanceolate, width/length ratio 0.15-0.28, apices acuminate to acute.
Lowest lemmas	3.5-6 mm, mostly smooth, apices scabridulous, unawned or awned to 2.5 mm.
Distal lemmas	scabrous.
Awns of distal lemmas	present, 3-9 mm, from slightly to evidently bent.
Anthers	0.5-1.8 mm.

Chromosome Number(s)

2n = 14

Typical Habitat(s)

Found in moist to wet places from 0-1135 meters.

Nativity / Range

Found in the eastern and southeastern United States.

Similar Species

Hybrids with S. obtusata, called Sphenopholis xpallens (Biehler) Scribn., differ from S. pensylvanica in having shorter spikelets and shorter awns on the distal lemmas. They differ from S. obtusata in having awns on the distal lemmas.

Name/Synonymy Publication Info

Sphenopholis pensylvanica [as "pennsylvanica"] (L.) Hitchc., Amer. J. Bot. 2:304 (1915). Avena pensylvanica L., Sp. pl. 1:79 (1753); Trisetum pensylvanicum [as "pennsylvanica"] (L.) P. Beauv. ex Roemer & Schultes, Syst. veg. 2:658 (1817); Arrhenatherum pensylvanicum [as "pennsylvanicum"] (L.) Torrey, Fl. n. middle United States 1:130 (1823). LEC: LINN 95.3; U.S.A., Pennsylvania; P. Kalm [Hitchc., Contr. U.S. Natl. Herb. 123:123 (1908)].

Avena palustris Michx., Fl. bor.-amer. 1:72 (1803); Trisetum palustre (Michx.) Torrey, Fl. n. middle United States 1:131 (1823); Sphenopholis palustris (Michx.) Scribner, Rhodora 8:145 (1906). HOL: P (P-MICH); U.S.A., Georgia and "Carolina" [published locality; specimen labelled "Georgia"]; A. Michaux.

Aira pallens var. aristata Muhl., Cat. pl. Amer. sept. 11 (1813). TYPE: U.S.A.

Arrhenatherum kentuckensis Torrey, Fl. n. middle United States 1:131 (1823). TYPE: U.S.A., Kentucky; C.S. Rafinesque.

Trisetum ludovicianum Vasey, Bull. Torrey Bot. Club 12:6 (1885). TYPE: U.S.A., Louisiana: Pointe ? la Hache; 1883; A.B. Langlois.

Sphenopholis palustris subsp. flexuosa Scribner, Rhodora 8:143 (1906); Sphenopholis palustris var. flexuosa Scribner ex Rob., Rhodora 10:65 (1908); Sphenopholis pensylvanica [as "pennsylvanica"] var. flexuosa (Scribner) F.T. Hubb., Rhodora 18:234 (1916). LEC: US 868646; U.S.A., Delaware: Wilmington; 1874; A. Commons 274 [Erdman, Iowa State Coll. J. Sci. 39:329 (1965)].

Treatment From

T.F. Daniel. Sphenopholis in Flora of North America, volume 24. In prep. Oxford University Press.

Vegetative Morphology