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 hirtulum

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms 50–100 cm long; 2–3 -noded. Lateral branches lacking. Leaf-sheaths smooth; glabrous on surface, or pubescent. Ligule an eciliate membrane; 1 mm long; erose. Leaf-blades filiform; involute; 10–25 cm long; 1–2 mm wide; firm, or flaccid. Leaf-blade surface smooth, or scaberulous; glabrous, or pubescent.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 10–20 cm long. Primary panicle branches 2 -nate; 2–6 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 8–11 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1.5–2 mm long; pilose; hairy above; with 1.5–2 mm long hairs. Floret callus pubescent. Floret callus hairs 0.5 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny. Lower glume lanceolate; 3.5–6 mm long; 0.5–0.9 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 7 mm long; 0.8–1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 7–8.5 mm long; cartilaginous; without keel; 5 -veined. Lemma surface scabrous; rough above. Lemma apex dentate; 2 -fid; awned; 3 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 12–15 mm long overall; with twisted column. Column of lemma awn 5–7 mm long. Lateral lemma awns arising on apex of lobes; 1 mm long. Palea 6–6.5 mm long. Palea keels ciliolate.

FLOWER Anthers 3; 1.5–2 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.