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.

Agrostis imberbis

HABIT Perennial; caespitose; clumped densely. Rhizomes elongated. Butt sheaths yellow. Culms geniculately ascending; 30–65 cm long. Leaf-sheaths 3–11 cm long; antrorsely scabrous. Ligule an eciliate membrane; 5–8 mm long; scaberulous on abaxial surface; entire, or lacerate; acute. Leaf-blades filiform; conduplicate, or convolute; 3–11 cm long; 0.5–1 mm wide; stiff; mid-green. Leaf-blade surface scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; 8–15 cm long; contracted about primary branches. Primary panicle branches whorled at most nodes. Panicle axis smooth. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scaberulous; puberulous; tip widened.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 2.8–3.1 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus glabrous, or sparsely hairy.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of upper glume; membranous; purple; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 2.8–3.1 mm long; 1.2–1.3 length of adjacent fertile lemma; membranous; purple; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 2.1–2.5 mm long; hyaline; without keel; 5 -veined. Lemma surface scaberulous; rough above and on veins. Lemma apex truncate; muticous, or mucronate. Principal lemma awn dorsal. Palea absent or minute.

FLOWER Lodicules 2; 0.4 mm long; membranous. Anthers 3; 1.2–1.8 mm long.

FRUIT Caryopsis with adherent pericarp; ovoid; 1.5–1.6 mm long. Hilum linear.

DISTRIBUTION South America: western South America and southern South America.

NOTES Aveneae. Fl Pat 1995.

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