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.

Pentameris trisetoides

HABIT Annual; caespitose. Glands raised crateriform. Culms 30–60 cm long; 2–3 -noded. Leaves mostly basal. Leaf-sheaths glabrous on surface, or hirsute; with tubercle-based hairs. Leaf-sheath oral hairs lacking. Ligule a fringe of hairs. Leaf-blades 10 cm long; 2 mm wide; stiff. Leaf-blade surface glabrous, or hirsute; hairy adaxially; with tubercle-based hairs. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; dense, or loose; 3–7 cm long; 1–4 cm wide. Panicle branches glabrous in axils.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; glandular.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; without rhachilla extension, or with a barren rhachilla extension. Spikelets cuneate; laterally compressed; 4–5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; shiny; gaping. Lower glume elliptic; 4–5 mm long; 1 length of upper glume; membranous; glandular; 1-keeled; 1 -veined. Lower glume primary vein smooth, or scaberulous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume elliptic; 4–5 mm long; 2–2.5 length of adjacent fertile lemma; membranous; glandular; 1-keeled; 1 -veined. Upper glume primary vein smooth, or scaberulous. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 2 mm long; membranous; without keel; 5–9 -veined. Lemma surface villous. Lemma apex dentate; 2 -fid; awned; 3 -awned. Principal lemma awn from a sinus; geniculate; 6–7 mm long overall; with twisted column. Lateral lemma awns arising on apex of lobes; 1–2 mm long; shorter than principal. Palea 0.9 length of lemma. Rhachilla extension 0–0.05 length of fertile floret.

FLOWER Lodicules 2; cuneate; fleshy; glabrous. Anthers 3; 0.5–0.7 mm long.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Africa: northeast tropical.

NOTES Arundineae. Linder.

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