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 lyallii

HABIT Annual; caespitose; clumped loosely. Stolons absent, or present. Basal innovations extravaginal. Culms erect, or geniculately ascending; 10–50 cm long. Leaf-sheaths smooth, or scaberulous. Ligule an eciliate membrane; 0.6–4 mm long; scaberulous on abaxial surface; erose, or lacerate; truncate. Leaf-blades flat, or conduplicate; 2–15 cm long; 0.3–3.5 mm wide. Leaf-blade surface scabrous; rough adaxially, or on both sides. Leaf-blade margins scaberulous. Leaf-blade apex abruptly acute.

INFLORESCENCE Inflorescence a panicle; deciduous as a whole. Peduncle scaberulous above; fracturing.

Panicle open; elliptic; effuse; 4–25 cm long; 1–16 cm wide. Primary panicle branches spreading. Panicle branches scaberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension, or with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 2.3–4.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pilose. Floret callus hairs 0.5–1 mm long; 0.33 length of lemma.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma; gaping. Lower glume elliptic, or ovate; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume surface scabrous; rough above. Lower glume apex acute. Upper glume elliptic, or ovate; 2.3–4.5 mm long; 1.3–2 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume surface scabrous; rough above. Upper glume apex acute.

FLORETS Fertile lemma elliptic, or oblong; 2–2.5 mm long; hyaline; without keel; 5 -veined. Lemma lateral veins excurrent. Lemma surface puberulous; hairy all along, or below. Lemma apex truncate; awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 2–6 mm long overall; with twisted column. Palea 0.5–1 length of lemma; hyaline; 2 -veined. Rhachilla extension 0.5–1 mm long; sparsely hairy; with 0.5–1 mm long hairs.

FLOWER Lodicules 2; linear; 0.7–0.9 mm long; membranous; acute. Anthers 3; 0.6–1.2 mm long.

FRUIT Caryopsis with adherent pericarp; 1.2–2 mm long.

DISTRIBUTION Australasia: New Zealand.

NOTES Aveneae. Edgar 1997.

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