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 newtonii

HABIT Perennial. Culms slender; 60–90 cm long; 2–3 -noded. Culm-internodes smooth; distally glabrous. Leaf-sheaths mostly shorter than adjacent culm internode; striately veined; smooth; glabrous on surface. Ligule an eciliate membrane; 2 mm long; truncate. Leaf-blades 7–12 cm long; 2.5 mm wide. Leaf-blade surface scaberulous; rough adaxially; glabrous. Leaf-blade margins scaberulous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 15–18 cm long. Primary panicle branches 2 -nate; simple, or sparsely divided; 3–7 cm long. Panicle axis scaberulous (above). Panicle branches capillary; flexuous; scaberulous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–4 mm long.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 11–14 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 3–3.5 mm long; pilose; hairy above; with 2–3 mm long hairs. Floret callus 0.75 mm long; pilose; obtuse.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 7–8 mm long; 0.7–0.75 length of upper glume; hyaline; 1-keeled; 4–5 -veined. Lower glume primary vein scaberulous. Lower glume apex acuminate. Upper glume lanceolate; 10–11 mm long; 1–1.1 length of adjacent fertile lemma; hyaline; 1-keeled; 5–7 -veined. Upper glume primary vein scaberulous. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 9–11 mm long; cartilaginous; much thinner above; without keel; 9–11 -veined. Lemma surface granulose. Lemma apex dentate; 2 -fid; setaceously attenuate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 10–18 mm long overall; with twisted column. Column of lemma awn 6–7 mm long. Palea oblong; 7–8 mm long. Palea keels ciliolate; adorned above. Rhachilla extension pilose.

FLOWER Anthers 3. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; oblong; 4 mm long; hairy at apex. Hilum linear.

DISTRIBUTION Africa: southern tropical.

NOTES Aveneae. FTA 1998.

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