GrassBase - The Online World Grass Flora


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

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

Agrostis umbellata

HABIT Annual, or perennial; short-lived; caespitose. Culms erect; 20–65 cm long; 2–3 -noded. Culm-internodes brown; distally glabrous. Lateral branches lacking. Leaf-sheaths striately veined; glabrous on surface. Ligule an eciliate membrane; 2.5–3 mm long; glabrous on abaxial surface; erose; acute. Leaf-blades 3–8 cm long; 1–2 mm wide. Leaf-blade surface scaberulous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; effuse; 8–13 cm long; 5–10 cm wide. Primary panicle branches whorled at most nodes; branching divaricately. Panicle axis smooth. Panicle branches scaberulous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 8–22 mm long; scabrous; tip widened.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 2.7–4 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus sparsely hairy; hairy on the margins.

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 asperulous. Lower glume apex acuminate. Upper glume lanceolate; 2.7–4 mm long; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume surface asperulous. Upper glume apex acuminate.

FLORETS Fertile lemma elliptic; 1.8–2.2 mm long; hyaline; without keel; 5 -veined. Lemma surface scaberulous. Lemma apex erose; truncate; awned; 1 -awned. Principal lemma awn subapical; straight; 1.4–2.5 mm long overall; clearly exserted from spikelet. Palea 0.2–0.4 mm long; 0.1–0.2 length of lemma; 0 -veined.

FLOWER Lodicules 2; 0.3 mm long; membranous. Anthers 3; 1–1.4 mm long.

FRUIT Caryopsis with adherent pericarp; 1.6–1.7 mm long. Hilum elliptic. Endosperm farinose.

DISTRIBUTION South America: southern South America.

NOTES Aveneae. Rugolo & Molina 2001.

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