GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Merostachys retrorsa

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms 200–250 cm long; woody. Culm-internodes terete; distally glabrous. Lateral branches dendroid. Branch complement many; flabellate. Leaf-sheaths papillose; outer margin hairy. Leaf-sheath oral hairs setose; 5–10 mm long. Ligule a ciliolate membrane; 0.2 mm long. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.2–0.4 cm long. Leaf-blades oblong, or ovate; 10–20 cm long; 20–38 mm wide. Leaf-blade midrib indistinct. Leaf-blade venation with obscure cross veins. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes; bracteate at pedicel base. Peduncle 6–17 cm long.

Racemes 1; single; unilateral; 4–8 cm long. Rhachis angular; villous on surface; terminating in a sterile spikelet. Spikelet packing broadside to rhachis; contiguous. Rhachis internodes 2–10 mm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–2 mm long; ciliate.

STERILE SPIKELETS Apical sterile spikelets rudimentary.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 16–17 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate; clasping; 6–7 mm long; chartaceous; 1-keeled; 0 -veined. Lower glume lateral veins absent. Lower glume surface puberulous. Lower glume margins ciliate. Lower glume apex acute. Upper glume lanceolate; 8–9 mm long; membranous; 1-keeled; 5 -veined. Upper glume surface glabrous. Upper glume margins ciliate. Upper glume apex acute; awned; 1 -awned. Upper glume awn 1 mm long.

FLORETS Fertile lemma lanceolate; 13–14 mm long; coriaceous; shiny; without keel; rounded except near apex. Lemma surface glabrous. Lemma apex acute; mucronate. Palea 1 length of lemma. Palea surface pilose; hairy above. Rhachilla extension 1 mm long.

FLOWER Lodicules 3; 3–4 mm long; veined; ciliate. Anthers 3. Stigmas 2.

FRUIT Caryopsis with free brittle pericarp.

DISTRIBUTION South America: northern South America.

NOTES Bambuseae. McClure 2001.

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