Aulonemia robusta

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms erect; 200–400 cm long; 10–25 mm diam.; woody. Culm-internodes terete; hollow; distally mealy, or glabrous. Culm-nodes swollen; with distinct supra-nodal ridge. Lateral branches dendroid. Buds or branches absent from lower quarter of culm. Bud complement 1. Branch complement one; solitary. Culm-sheaths 12–12.5 cm long; without auricles; setose on shoulders; shoulders with 20–30 mm long hairs. Culm-sheath blade lanceolate; reflexed; 6–8.5 cm long. Leaf-sheaths without keel; glabrous on surface; outer margin hairy. Leaf-sheath oral hairs setose; erect; 30–40 mm long. Ligule an eciliate membrane; 2–8 mm long. Collar with external ligule. Leaf-blade base broadly rounded; with a brief petiole-like connection to sheath; petiole 0.5–0.7 cm long. Leaf-blades reflexed; ovate; 19–32 cm long; 5–13.5 mm wide. Leaf-blade venation without cross veins. Leaf-blade surface scabrous; rough abaxially. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 35–50 cm long. Primary panicle branches ascending. Panicle axis smooth. Panicle branches with prominent pulvini.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels angular; 2–10 mm long; smooth.

FERTILE SPIKELETS Spikelets comprising 4–7 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 11–16 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1.5–2 mm long; glabrous, or pubescent. Floret callus evident; 1–2 mm long.

GLUMES Glumes persistent; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 2.5–4 mm long; membranous; without keels; 3 -veined. Lower glume apex acute; awned; 1 -awned. Lower glume awn 0.5–1 mm long. Upper glume ovate; 4–4.7 mm long; membranous; without keels; 5–7 -veined. Upper glume surface puberulous; hairy at apex. Upper glume apex acuminate.

FLORETS Fertile lemma ovate; 5.3–6.7 mm long; chartaceous; without keel; 7–9 -veined. Lemma surface puberulous. Lemma apex acuminate. Palea 5.3–6.4 mm long; 2 -veined. Palea surface pubescent; hairy on back. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; 0.9–1.2 mm long; ciliate. Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: northern South America and western South America.

NOTES Bambuseae. Clark 1995.

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