Chusquea aperta

HABIT Perennial. Culms 100–200 cm long; 5–10 mm diam.; woody; without nodal roots. Culm-internodes terete; solid; smooth. Culm-nodes swollen; with distinct supra-nodal ridge. Lateral branches dendroid; infravaginal. Branch complement many; in a clump; with 1 branch dominant; thinner than stem. Culm-sheaths deciduous but leaving a persistent girdle; smooth. Culm-sheath ligule 2–3 mm high. Culm-sheath blade triangular; deciduous; 1 cm long. Ligule an eciliate membrane; 2–9 mm long; obtuse, or acute. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.2–0.3 cm long. Leaf-blades lanceolate; 7–12 cm long; 8–15 mm wide; light green. Leaf-blade venation with distinct cross veins (beneath). Leaf-blade surface glabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle. Peduncle 6–12 cm long.

Panicle open; ovate; 7–11 cm long; contracted about primary branches. Primary panicle branches spreading; 4–6 cm long. Panicle axis angular; glabrous. Panicle branches angular; glabrous.

Spikelets appressed; solitary. Fertile spikelets pedicelled. Pedicels 7–14 mm long; glabrous.

FERTILE SPIKELETS Spikelets comprising 2 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 6–8 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.3–0.5 mm long; 0.75 length of upper glume; membranous; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 0.4–0.8 mm long; 0.07–0.1 length of adjacent fertile lemma; without keels; 0 -veined. Upper glume primary vein absent. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Basal sterile florets similar; barren; with palea (rarely in upper), or without significant palea; attached to and deciduous with the fertile. Lemma of lower sterile floret elliptic; 4–4.6 mm long; chartaceous; 1–3 -veined; acuminate. Lemma of upper sterile floret ovate; 4.5–5.1 mm long; chartaceous; acuminate. Fertile lemma ovate; 5.7–7.1 mm long; coriaceous; without keel; 7 -veined. Lemma apex acuminate. Palea 5.5–6.8 mm long; 4–6 -veined. Palea keels contiguous above a sulcus.

FLOWER Lodicules 3; membranous. Anthers 3; 4–5 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; apex unappendaged.

DISTRIBUTION North America: Mexico.

NOTES Bambuseae. Clarke 1995.

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