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 tysonii

HABIT Perennial; caespitose. Stolons present. Butt sheaths glabrous; persistent and investing base of culm; with compacted dead sheaths. Glands absent. Culms 30–50 cm long; 3–5 -noded. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths glabrous on surface. Leaf-sheath oral hairs bearded. Ligule a fringe of hairs. Leaf-blades filiform; convolute; 30 cm long; 0.5–2 mm wide; stiff; eglandular. Leaf-blade surface hirsute; hairy adaxially. Leaf-blade margins smooth. Leaf-blade apex obtuse.

INFLORESCENCE Inflorescence a panicle; comprising 50 fertile spikelets.

Panicle open; ovate; 6–10 cm long; 6–9 cm wide. Panicle branches eglandular; glabrous in axils.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; 1.2 length of fertile spikelet; eglandular; smooth.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; without rhachilla extension. Spikelets cuneate; laterally compressed; 6–10 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; gaping. Lower glume elliptic; 6–10 mm long; 1 length of upper glume; membranous; mid-green; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 6–10 mm long; 1.7–2.8 length of adjacent fertile lemma; membranous; mid-green; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma oblong; 3.5 mm long; membranous; without keel; 5–9 -veined. Lemma surface villous. Lemma apex lobed; 2 -fid; with lobes 2 mm long; awned; 3 -awned. Principal lemma awn from a sinus; geniculate; 3–11 mm long overall; with twisted column. Lateral lemma awns arising on inner edge of lobes; 1–5 mm long; equalling glumes, or enclosed by glumes; shorter than principal. Palea surface villous; hairy above.

FLOWER Lodicules 2; cuneate; fleshy; glabrous. Anthers 3; 3.2–4 mm long; brown.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Africa: south.

NOTES Arundineae. Linder 1992.

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