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.

Phaenanthoecium koestlinii

HABIT Perennial. Culms decumbent, or prostrate; 10–30 cm long. Leaves cauline. Ligule a fringe of hairs. Leaf-blades spreading; flat, or convolute; 0.5–4 cm long; 1–1.5 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; flexuous; 2–4 cm long; bearing few fertile spikelets; bearing 2–6 fertile spikelets on each. Rhachis scabrous on surface; puberulous on surface. Spikelet packing lax; irregular.

Spikelets appressed; solitary. Fertile spikelets pedicelled. Pedicels filiform; 1–2 mm long.

FERTILE SPIKELETS Spikelets comprising 5–9 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 9–12 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes eventually visible between lemmas. Floret callus bearded; obtuse. Floret callus hairs 0.4–0.5 length of lemma.

GLUMES Glumes persistent; similar; shorter than spikelet; similar to fertile lemma in texture. Lower glume oblong; 2.5–3 mm long; 0.8 length of upper glume; membranous; without keels, or 1-keeled; 1–3 -veined. Lower glume apex emarginate, or obtuse. Upper glume oblong; 3–3.5 mm long; 0.8–0.9 length of adjacent fertile lemma; membranous; without keels; 3–4 -veined. Upper glume apex emarginate, or obtuse.

FLORETS Fertile lemma elliptic; 3–4 mm long; membranous; much thinner on margins; without keel; 9 -veined. Lemma surface with marginal hair tufts; bearing 4 hair tufts in all. Lemma apex lobed; 2 -fid; incised 0.25 of lemma length; awned; 3 -awned. Principal lemma awn from a sinus; geniculate; 12–18 mm long overall; with twisted column. Column of lemma awn 2–2.5 mm long. Lateral lemma awns arising on apex of lobes; 7–11 mm long; shorter than principal. Palea 1 length of lemma; 2 -veined. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; cuneate; fleshy; ciliate. Anthers 3; 1 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; oblong; concavo-convex; 2 mm long. Embryo 0.25 length of caryopsis. Hilum linear; 0.8 length of caryopsis.

DISTRIBUTION Africa: northeast tropical. Asia-temperate: Arabia.

NOTES Arundineae. FTA.

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