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.

Didymogonyx longispiculatum

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms erect; inclined at the tip; 800–1500 cm long; 40–60 mm diam.; woody. Culm-internodes alternately elongated and bunched; terete; 90–120 cm long; distally glabrous. Lateral branches dendroid; intravaginal; arising from mid culm and upper culm. Branch complement in a clump; subtended by a bare patch above the node; with subequal branches. Culm-sheaths 10–18 cm long; 1.2–1.7 times as long as wide; glabrous; auriculate; with 3–4 mm high auricles; setose on shoulders; shoulders with curved hairs; shoulders with 2–3 mm long hairs. Culm-sheath ligule 0.8–1 mm high; fimbriate. Culm-sheath blade ovate; 7–15 cm long; 30–70 mm wide; pubescent and with ciliate margins. Leaves 5–7 per branch. Leaf-sheaths without keel; glabrous on surface; outer margin hairy. Leaf-sheath oral hairs setose; curly; 10–13 mm long. Ligule absent. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.4–0.6 cm long; petiole pubescent. Leaf-blades linear; 10.5–19 cm long; 4–12 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; 13–25(–40) cm long; bearing (9–)15–20(–25) fertile spikelets on each. Rhachis semiterete; glabrous on surface; scabrous on margins.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.5–2.5 mm long.

FERTILE SPIKELETS Spikelets comprising 5–12 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; (50–)80–100(–120) mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes clavate; 5–9 mm long; glabrous.

GLUMES Glumes several; 3–4 empty glumes; persistent; shorter than spikelet. Lower glume linear; 4–7 mm long; chartaceous; 1 -veined. Lower glume lateral veins absent. Upper glume lanceolate; 4–9 mm long; 5–7 -veined. Upper glume margins eciliate, or ciliolate. Upper glume mucronate.

FLORETS Fertile lemma ovate; narrowly proportioned; 16–18 mm long; 4–6 mm wide; chartaceous; shiny; without keel; 13–17 -veined. Lemma surface glabrous. Lemma apex acute; mucronate. Palea 6–11 mm long; 0.5 length of lemma; 2-keeled. Palea keels ciliolate. Palea surface glabrous, or puberulous; hairy on back; hairy above. Palea apex dentate; 2 -fid; ciliate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; 3–4 mm long; veined; ciliate. Anthers 3; 5–7 mm long; purple.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: western South America.

NOTES Bambuseae. Londono & Clark 2002.

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