Thyrsostachys Gamble

Abstract

Arborescent bamboos. Rhizomes sympodium, culm-necks short. Clumps dense, culms erect; internodes terete, glabrous, culm-walls thick or solid at the bottom; sheath nodes prominent; culm-nodes flat or slightly prominent. Branching from upper nodes, 3 to many branches on nodes, dominant branches absent. Culm-sheaths papery to leathery, deciduous or persistent; auricles and oral setae absent; ligules short; blades erect. Leaves several for each branchlet; auricles absent; blades small, lanceolate or narrowly lanceolate, transverse veins inconspicuous. Flowering branches leafless, inflorescence panicle-like, large, pseudospikelets subtended by bracts, loosely arranged on each node; 3–4 florets for each pseudospikelet, the upmost one reduced or sterile; rachilla disarticulated, internodes short, pubescent; glumes 1 or 2; lemma larger than glumes; palea membranous, longer than lemma, 2-keeled, keels ciliate, apex deeply bifid, palea of the sterile florets without prominent keels and apex inconspicuously bifid; lodicules absent or seldom 2–3; stamens 6, filaments free; ovary petiolate, apex swollen when fresh, style 1, slender, stigmas 1–3, plumose. Caryopses cylindrical, grooved, apex beaked; pericarp rigid, adnate to seeds. New shoots in autumn.