Piptatherum canadense

(Poir.) Dorn
Common names: Canadian piptatherum Oryzopsis du canada
Synonyms: Oryzopsis canadensis
Treatment appears in FNA Volume 24. Treatment on page 146.

Plants cespitose, not rhizomatous. Culms 30-90 cm, glabrous; basal branching mostly intravaginal. Leaves basally concentrated; sheaths smooth or scabridulous; ligules 1-4 mm, hyaline, truncate, rounded, or acute; basal blades 4-15 cm long, 1-1.5 mm wide when flat, 0.5-0.8 mm in diameter when folded or convolute. Panicles 9-15 cm, lower nodes with 1-2 branches; branches 1-6 cm, somewhat flexuous, ascending to divergent. Glumes subequal, 3-6 mm long, 1.3-2 mm wide, ovate, 1-3-veined, apices acute to mucronate; florets 2.2-4.5 mm, obovoid, dorsally compressed; calluses 0.2-0.5 mm, hairy, disarticulation scars elliptic; lemmas coriaceous, evenly pubescent, tan at maturity, margins widely separated even when immature; awns 5-15 mm, persistent, once- or twice-geniculate, first segments strongly twisted; paleas similar to the lemmas in length, texture, and pubescence; anthers 1-2 mm; ovaries developing 2 conelike style bases, each bearing a single, unbranched style. Caryopses about 2.5 mm long, 0.5 mm thick; hila linear, almost equaling the caryopses. 2n = 22.

Discussion

Piptatherum canadense grows in grasslands and open woods, from the British Columbia-Alberta border east to Newfoundland, extending south into the Great Lakes region and the northeastern United States. Its persistent, longer awns distinguish P. canadense from P. pungens.

Selected References

None.

Lower Taxa

None.