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 longifolium

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms 30–90 cm long; 3–4 -noded. Lateral branches lacking. Leaf-sheaths smooth; glabrous on surface. Ligule an eciliate membrane; 1.5 mm long. Leaf-blades filiform; convolute; 20–40 cm long; 1–1.5 mm wide. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; 10–20 cm long. Primary panicle branches simple, or sparsely divided; 2–5 cm long. Panicle branches capillary; scaberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–4 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 8–10 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2 mm long; eventually visible between lemmas; pilose; hairy above; with 3–4 mm long hairs. Floret callus 0.75 mm long; pilose. Floret callus hairs 1.5–2 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny. Lower glume lanceolate; 5–6.5 mm long; 0.66–0.75 length of upper glume; hyaline; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 8–9 mm long; 0.8–0.9 length of adjacent fertile lemma; hyaline; 1-keeled; 3 -veined. Upper glume primary vein scaberulous. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 10 mm long; cartilaginous; without keel; 5 -veined. Lemma surface smooth. Lemma apex dentate; 2 -fid; awned; 3 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 15–25 mm long overall; with twisted column. Column of lemma awn 5–8 mm long. Lateral lemma awns arising on apex of lobes; 2 mm long. Palea 6 mm long. Palea keels ciliolate.

FLOWER Anthers 3; 2–3 mm long. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; hairy at apex. Hilum linear.

DISTRIBUTION Africa: south.

NOTES Aveneae. Schweickerdt 1993.

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