GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Calamagrostis montanensis

HABIT Perennial; culms solitary. Rhizomes elongated. Butt sheaths papery. Culms 15–35 cm long. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths smooth. Ligule an eciliate membrane; 3–5 mm long; erose, or lacerate; obtuse, or acute. Leaf-blades erect; involute; 1–3 mm wide; stiff. Leaf-blade surface scabrous. Leaf-blade apex hardened.

INFLORESCENCE Inflorescence a panicle. Peduncle antrorsely scabrous above.

Panicle contracted, or spiciform; linear; 3–10 cm long; 1–1.5 cm wide.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 4–5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus bearded. Floret callus hairs 0.33–0.66 length of lemma.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume surface smooth, or scabrous. Lower glume apex acuminate. Upper glume lanceolate; 4–5 mm long; 1.1 length of adjacent fertile lemma; membranous; 1-keeled; 1–3 -veined. Upper glume primary vein scabrous. Upper glume surface smooth, or scabrous. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 3.5–4.5 mm long; membranous; without keel; 5 -veined. Lemma apex dentate; 4 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.33 way up back of lemma; geniculate; 2.5–3 mm long overall; not or scarcely exserted from spikelet; with twisted column. Palea 3–4 mm long. Rhachilla extension 1.5 mm long; 0.33–0.5 length of fertile floret; villous.

FLOWER Lodicules 2; 0.6 mm long. Anthers 3; 2 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform. Disseminule comprising a floret.

DISTRIBUTION North America: western Canada, northwest USA, and north-central USA.

NOTES Aveneae. Fl Pac NW 1994.

Please cite this publication as detailed in How to Cite Version: 27th January 2014.