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 billardieri

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 15–45 cm long; 3 -noded. Culm-internodes antrorsely scabrous. Culm-nodes glabrous. Leaf-sheaths loose; antrorsely scabrous. Ligule an eciliate membrane; 4–8 mm long; scaberulous on abaxial surface; lacerate; obtuse. Leaf-blades 5–40 cm long; 2–8 mm wide. Leaf-blade surface ribbed; papillose. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle; deciduous as a whole; embraced at base by subtending leaf. Peduncle antrorsely scabrous above; fracturing.

Panicle open; pyramidal. Primary panicle branches whorled at lower nodes; branching divaricately. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 2–10 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 4.5–7.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent. Floret callus hairs 0.2–0.8 mm long; 0.04–0.1 length of lemma.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma; gaping. Lower glume lanceolate; 4.5–7.5 mm long; 1.1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume margins ciliolate. Lower glume apex acuminate. Upper glume lanceolate; 4–7 mm long; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume surface scabrous. Upper glume margins ciliolate. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 3–4.5 mm long; hyaline; shiny; without keel; 5 -veined. Lemma lateral veins obscure; extending close to apex. Lemma surface smooth, or asperulous. Lemma apex dentate; 4 -fid; with outer lobes longer; truncate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 6–8 mm long overall; with twisted column. Palea 0.66 length of lemma; hyaline. Rhachilla extension 0.8–2.5 mm long; pilose; with 1.5 mm long hairs.

FLOWER Lodicules 2; membranous. Anthers 3; 0.8–1 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION Australasia: Australia and New Zealand.

NOTES Aveneae. Vickery 1994.

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