Merostachys polyantha

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms 600–800 cm long; woody. Culm-internodes terete; hollow; light green and purple; mottled; retrorsely scabrous; distally pruinose and pubescent. Lateral branches dendroid. Bud complement 1. Branch complement many; flabellate. Culm-sheaths deciduous but leaving a persistent girdle; hairy on margins; auriculate; setose on shoulders; shoulders with 10–12 mm long hairs. Culm-sheath ligule ciliolate. Leaf-sheaths striately veined; retrorsely scabrous; glabrous on surface; outer margin hairy. Leaf-sheath oral hairs setose. Leaf-sheath auricles falcate. Ligule a ciliolate membrane. Collar with external ligule. Leaf-blade base broadly rounded, or cordate; asymmetrical; with a brief petiole-like connection to sheath; petiole 0.4–0.8 cm long; petiole glabrous, or pubescent. Leaf-blades oblong; 8–15 cm long; 20–35 mm wide. Leaf-blade midrib indistinct. Leaf-blade venation with 10–16 secondary veins; with distinct cross veins. Leaf-blade surface glabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes; bracteate at pedicel base. Peduncle pubescent above.

Racemes 1; single; arcuate; unilateral; 2.5–6.5 cm long; bearing 10–26 fertile spikelets on each. Rhachis pubescent on surface; terminating in a sterile spikelet. Spikelet packing broadside to rhachis; crowded; regular; 2 -rowed. Rhachis internodes 1.5–4 mm long.

Spikelets pectinate. Fertile spikelets sessile.

STERILE SPIKELETS Apical sterile spikelets barren; 7–8 in number.

FERTILE SPIKELETS Spikelets comprising 5–10 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; compressed slightly; 20–55 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes clavate; 2–4 mm long; pubescent.

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate; 4 mm long; chartaceous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface puberulous. Lower glume margins ciliate. Lower glume apex acuminate. Upper glume ovate; 6–9 mm long; chartaceous; 1-keeled; 5 -veined. Upper glume surface puberulous. Upper glume margins ciliolate. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 10–20 mm long; coriaceous; without keel; 5 -veined. Lemma surface pubescent. Lemma margins ciliolate; hairy above. Lemma apex acute. Palea 1 length of lemma; coriaceous; 2 -veined. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; veinless, or veined. Anthers 3; purple. Stigmas 2. Ovary glabrous.

FRUIT Caryopsis with free brittle pericarp.

DISTRIBUTION South America: Brazil.

NOTES Bambuseae. McClure 1995.

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