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.

Aulonemia purpurata

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms woody. Culm-internodes terete; with small lumen. Lateral branches dendroid. Bud complement 1. Branch complement in a clump; subtended by a bare patch above the node; with subequal branches. Leaf-sheaths striately veined; glabrous on surface. Leaf-sheath oral hairs setose; 5–10 mm long. Leaf-sheath auricles erect. Ligule a ciliolate membrane; 0.5 mm long. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.1–0.2 cm long; petiole glabrous. Leaf-blades lanceolate; 5–10.5 cm long; 6–12 mm wide. Leaf-blade venation with 8–10 secondary veins; without cross veins. Leaf-blade surface pubescent; sparsely hairy; hairy abaxially. Leaf-blade margins cartilaginous; scaberulous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle 10–15 cm long.

Racemes 1; single; paucilateral; 5–10 cm long. Rhachis angular; scabrous on margins. Spikelet packing broadside to rhachis.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 2–3 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 4–6 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 35–45 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes clavate; 4–7 mm long; eventually visible between lemmas.

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate; 3–4 mm long; chartaceous; without keels; 4 -veined. Lower glume primary vein scabrous. Lower glume apex acute; awned; 1 -awned. Lower glume awn 1–2 mm long. Upper glume lanceolate; 7–8 mm long; purple; 1-keeled, or 2-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume surface glabrous to pubescent; hairy above. Upper glume margins ciliolate. Upper glume apex entire, or dentate; 2 -fid; acute; awned; 1 -awned. Upper glume awn 1–2 mm long.

FLORETS Fertile florets increasing in size upwards. Fertile lemma lanceolate; 10–11 mm long; chartaceous; purple; without keel; 7 -veined. Lemma surface scabrous. Lemma margins ciliate; hairy above. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 7 mm long overall. Palea 9–10 mm long; 0.9 length of lemma. Palea keels ciliolate. Palea surface scabrous; pubescent; hairy on back; hairy above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; 1.5–2 mm long; ciliate. Anthers 2; 7 mm long. Stigmas 2. Ovary umbonate; glabrous.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: northern South America.

NOTES Bambuseae. McClure 1995.

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