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.

Helictotrichon neesii

HABIT Perennial; caespitose. Rhizomes absent, or elongated. Butt sheaths distinctly ribbed; glabrous. Culms erect; 80–150 cm long; 1–2.5 mm diam.; 2–4 -noded. Culm-internodes terete, or elliptical in section; ridged. Culm-nodes glabrous. Leaf-sheaths ribbed; smooth, or scaberulous. Ligule an eciliate membrane; 6.5–8 mm long; acute. Leaf-blades flat, or involute; 15–37 cm long; 2–4 mm wide. Leaf-blade surface ribbed; grooved adaxially and abaxially; smooth to scabrous; pubescent; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; 15–37 cm long. Primary panicle branches 1–3 -nate; 7–14 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 10–20 mm long.

FERTILE SPIKELETS Spikelets comprising 2–5 fertile florets; with a barren rhachilla extension, or with diminished florets at the apex. Spikelets oblong; laterally compressed; 8–14 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate; 3.8–6.3 mm long; 0.6–0.8 length of upper glume; membranous; much thinner on margins; 1-keeled; 3–5 -veined. Lower glume apex acute. Upper glume lanceolate; 6.4–7.5 mm long; 1.1 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; 5–7 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 5.9–8.4 mm long; cartilaginous; without keel; 5–7 -veined. Lemma midvein ciliolate. Lemma surface scabrous, or papillose. Lemma apex dentate; 2(–4) -fid; with outer lobes shorter; with lobes 0.26–0.36 mm long; awned; 1 -awned. Principal lemma awn dorsal; arising 0.66–0.75 way up back of lemma; geniculate; 13.8–25.5 mm long overall; with 9–17.5 mm long limb; with twisted column. Column of lemma awn 4.8–6.5 mm long; scabrous; hirtellous. Palea 0.8–0.9 length of lemma. Palea keels ciliate. Palea surface papillose. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; 1.3–2.3 mm long; membranous; glabrous; acute. Anthers 3; 1.3–2.3 mm long; eventually exserted, or retained within floret. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; 2–3 mm long; light brown; glabrous. Embryo 0.1–0.2 length of caryopsis. Hilum linear; 0.35–0.45 length of caryopsis.

DISTRIBUTION Australasia: Australia.

NOTES Aveneae. Jacobs & Lap 1994.

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