Arundinella berteroniana

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 75–115 cm long; 1.5–2 mm diam. Culm-internodes hollow. Culm-nodes pubescent. Lateral branches lacking. Leaf-sheaths hispid; with tubercle-based hairs. Leaf-sheath oral hairs bearded. Ligule an eciliate membrane; 0.5 mm long. Leaf-blades 25–35 cm long; 3–6 mm wide. Leaf-blade midrib conspicuous. Leaf-blade surface pilose; hairy on both sides. Leaf-blade margins cartilaginous.

INFLORESCENCE Inflorescence a panicle; bearing juvenile spikelets at emergence.

Panicle open; lanceolate; dense; 20–40 cm long; 4–6 cm wide; contracted about primary branches. Primary panicle branches appressed; 10–15 cm long.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels glabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets cuneate; laterally compressed; 4.2–5.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus obtuse.

GLUMES Glumes persistent; dissimilar; exceeding apex of florets; thinner than fertile lemma; recurved at apex and gaping. Lower glume lanceolate; 3.2–4.5 mm long; 0.75 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume surface scabrous; rough on veins. Lower glume apex acuminate. Upper glume lanceolate; 2.5 length of adjacent fertile lemma; 1 length of spikelet; membranous; 1-keeled; 5 -veined. Upper glume apex caudate.

FLORETS Basal sterile florets male; with palea; persisting on inflorescence. Lemma of lower sterile floret similar to upper glume; ovate; membranous; 1-keeled; 3–5 -veined; acute. Fertile lemma lanceolate; 1.5–1.8 mm long; coriaceous; without keel; 3 -veined. Lemma lateral veins obscure. Lemma surface asperulous. Lemma margins involute; interlocking with palea keels. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; straight, or geniculate; 8–13 mm long overall; without a column, or with a straight or slightly twisted column. Palea with auriculate flaps; coriaceous; 2 -veined. Palea surface asperulous.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.6–0.7 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, Caribbean, western South America, Brazil, and southern South America.

NOTES Arundinelleae. Fl Costa Rica 1993.

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