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 subpatens

HABIT Perennial; caespitose; clumped densely. Culms erect; 20–50 cm long; 0.5–1 mm diam.; 2 -noded. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths smooth; glabrous on surface. Ligule an eciliate membrane; 3–5 mm long. Leaf-blades erect; filiform; conduplicate; 5–15 cm long; 0.6 mm wide. Leaf-blade surface ribbed; scaberulous; rough abaxially.

INFLORESCENCE Inflorescence a panicle. Peduncle 3–5 cm long.

Panicle open; ovate; 8–9 cm long. Primary panicle branches spreading; 2–8 -nate; whorled at most nodes. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–2 length of fertile spikelet; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 2.9–3.7 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus glabrous.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma; shiny; gaping. Lower glume oblong; 2.9–3.7 mm long; 1.1–1.2 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume oblong; 2.5–3.5 mm long; 1.5 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma ovate; 1.7–2.2 mm long; hyaline; without keel. Lemma lateral veins extending close to apex. Lemma apex dentate; 4 -fid; truncate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.25 way up back of lemma; geniculate; 3 mm long overall; with twisted column. Palea absent or minute.

FLOWER Lodicules 2; membranous. Anthers 3; 1–1.5 mm long; purple.

FRUIT Caryopsis with adherent pericarp; ovoid; 1.3–1.4 mm long. Hilum linear.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Aveneae. Fl Costaric 1993.

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