Poa macrocalyx

HABIT Perennial; culms solitary, or caespitose. Rhizomes elongated. Stolons present. Culms erect; 22–75 cm long. Culm-internodes terete; smooth. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths smooth; glabrous on surface. Ligule an eciliate membrane; 2.5–5.5 mm long; erose; truncate. Leaf-blades flat, or conduplicate; 4–12 cm long; 2–3 mm wide. Leaf-blade apex abruptly acute.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic, or ovate; dense, or loose; 4–12 cm long. Primary panicle branches ascending, or spreading. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–6 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 6–11.2 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes smooth. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume elliptic; 7 mm long; 1 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume elliptic; 4–8 mm long; 0.8–1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acute.

FLORETS Fertile lemma elliptic; elliptic in profile; 5–8 mm long; membranous; keeled; 5 -veined. Lemma midvein pubescent. Lemma surface scabrous; rough between veins; pubescent; hairy on veins. Lemma margins pubescent. Lemma apex acute. Palea 1 length of lemma. Palea keels scabrous; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 1.7–2.5 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

CLEISTOGENES AND VIVIPARY Vegetative proliferation occurs.

DISTRIBUTION Asia-temperate: Soviet far east and eastern Asia. North America: Subarctic.

NOTES Poeae. Fl Alaska 1994.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.