Chusquea exasperata

HABIT Perennial. Culms scandent; pendulous at the tip; 1000–1200 cm long; 13–25 mm diam.; woody; without nodal roots. Culm-internodes channelled; 14.5–24 cm long; distally glabrous, or pilose. Lateral branches dendroid; infravaginal. Bud prophyll 80–100 mm long. Branch complement many; in a clump; thinner than stem. Culm-sheaths persistent; 35.5–57 cm long; antrorsely scabrous. Culm-sheath ligule 1.5 mm high; ciliate. Culm-sheath blade triangular; indistinctly demarcated from sheath; erect; 0.8–1.2 cm long; scabrid, or pubescent. Ligule an eciliate membrane; 3–6 mm long; obtuse. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.3–0.4 cm long. Leaf-blades lanceolate; 9.2–24.2 cm long; 10–14 mm wide. Leaf-blade venation without cross veins. Leaf-blade surface glabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle; bracteate at branch bases and bracteate at pedicel base; embraced at base by subtending leaf.

Panicle open; linear; 8–14 cm long. Primary panicle branches appressed; 2.5–3.5 cm long. Panicle axis angular; scabrous; glabrous. Panicle branches angular; glabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels angular; 2–4 mm long; glabrous.

FERTILE SPIKELETS Spikelets comprising 2 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 10.7–11.3 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 1.9–2.2 mm long; membranous; without keels; 2 -veined. Lower glume surface scabrous. Lower glume apex acute. Upper glume ovate; 3–3.2 mm long; 0.25 length of adjacent fertile lemma; membranous; without keels; 3 -veined. Upper glume surface scabrous. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea; attached to and deciduous with the fertile. Lemma of lower sterile floret ovate; 4.9–5.5 mm long; 0.5 length of fertile lemma; chartaceous; 7–9 -veined; scabrous; acute; mucronate. Lemma of upper sterile floret ovate; 7.5–8.4 mm long; chartaceous; scabrous; acute; mucronate. Fertile lemma ovate; 10.1–10.3 mm long; coriaceous; without keel; 9–11 -veined. Lemma surface scabrous. Lemma apex acute. Palea 9.6–9.7 mm long; 4 -veined. Palea keels contiguous above a sulcus.

FLOWER Lodicules 3; 2 mm long; membranous; ciliate. Anthers 3; 4.5–5.4 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; apex unappendaged.

DISTRIBUTION South America: western South America.

NOTES Bambuseae. Clark 1995.

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