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.

Lachnagrostis lacunarum

HABIT Annual. Butt sheaths papery; glabrous. Culms erect, or geniculately ascending; 20–40 cm long; without nodal roots, or rooting from lower nodes. Leaf-sheaths loose; longer than adjacent culm internode; ribbed. Ligule an eciliate membrane; 3–6 mm long; acute. Leaf-blades 10–20 cm long; 1.5–2.5 mm wide. Leaf-blade surface ribbed; grooved adaxially and abaxially; scaberulous; rough adaxially.

INFLORESCENCE Inflorescence a panicle. Peduncle scaberulous above.

Panicle open; pyramidal; 6–12 cm long; 4–7 cm wide. Primary panicle branches 2–4 -nate. Panicle axis scabrous. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 2.75–4 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pilose.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma; gaping. Lower glume lanceolate, or elliptic; 1 length of upper glume; membranous; purple; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume surface scabrous. Lower glume apex acute. Upper glume lanceolate, or elliptic; 2.75–4 mm long; membranous; purple; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume surface scabrous. Upper glume apex acute.

FLORETS Fertile lemma oblong; 2–2.5 mm long; hyaline; without keel; 5 -veined. Lemma surface pubescent. Lemma apex dentate; 4 -fid; truncate; awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; straight, or geniculate; 1.5–3.25 mm long overall; with a straight or slightly twisted column. Column of lemma awn 1.5 mm long. Palea 0.9 length of lemma; hyaline; 2 -veined. Rhachilla extension 0.5 mm long; pubescent; with 0.5 mm long hairs.

FLOWER Lodicules 2; membranous. Anthers 3; 0.6–0.8 mm long.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Australasia: Australia.

NOTES Aveneae. Morris 1997.

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