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 rogerellisii

HABIT Perennial; caespitose. Culms slender; 30–60 cm long; 1–2 -noded. Culm-internodes distally glabrous. Lateral branches lacking. Leaves cauline. Ligule an eciliate membrane; 2 mm long; erose, or lacerate. Leaf-blades involute; 10–20 cm long; 1.5 mm wide. Leaf-blade surface scabrous; rough on both sides.

INFLORESCENCE Inflorescence a panicle; comprising 10–15 fertile spikelets.

Panicle open; ovate; loose; 8–10 cm long. Primary panicle branches simple, or sparsely divided. Panicle branches pubescent.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels unequal; pubescent.

FERTILE SPIKELETS Spikelets comprising 3–4 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 13–18 mm long; 3–4.5 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2.8–3.3 mm long; pilose; hairy all along but hairs longer above; with 0.5–4.5 mm long hairs. Floret callus 1 mm long; pilose.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny. Lower glume lanceolate; 5–8 mm long; 0.66 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume margins ciliate. Lower glume apex acute; mucronate. Upper glume lanceolate; 8.5–12 mm long; 0.8 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume margins ciliolate. Upper glume apex acute; mucronate.

FLORETS Fertile lemma oblong; 11–15 mm long; cartilaginous; purple; without keel; 5 -veined. Lemma lateral veins prominent. Lemma surface scaberulous. Lemma apex dentate; 2 -fid; with lobes 1–2 mm long; awned; 3 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 11–21.55 mm long overall; with twisted column. Lateral lemma awns arising on apex of lobes; 1–1.5 mm long. Palea keels ciliolate. Palea apex dentate; 2 -fid.

FLOWER Anthers 3; 3.8–4.5 mm long; yellow.

DISTRIBUTION Africa: south.

NOTES Aveneae. Mashau et al 2012.

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