Arberella dressleri

HABIT Perennial; caespitose. Culms erect; 30–35 cm long; 3–6 -noded. Culm-internodes solid. Culm-nodes constricted. Lateral branches lacking. Leaves cauline. Leaf-sheaths outer margin hairy. Ligule a ciliolate membrane; 0.8 mm long. Leaf-blade base asymmetrical; with a brief petiole-like connection to sheath; petiole 0.1–0.2 cm long; petiole pubescent. Leaf-blades lanceolate; 8–14 cm long; 15–30 mm wide. Leaf-blade surface glabrous. Leaf-blade margins serrulate; ciliate. Leaf-blade apex acute.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence (or some all male). Inflorescence a panicle; comprising 1 fertile spikelets (and 5–20 male); terminal and axillary. Axillary inflorescences present throughout the plant.

Panicle open; linear; 4–8 cm long; bearing few spikelets.

Sexes segregated; on unisexual branches; with male below. Spikelets solitary. Fertile spikelets pedicelled. Male spikelets pedicelled; 2 in a cluster. Pedicels clavate (female), or linear (male); scaberulous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 13–22 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; pubescent; truncate.

GLUMES Glumes deciduous; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume elliptic; 13–22 mm long; 1 length of upper glume; membranous; pallid; without keels; 9–11 -veined. Lower glume lateral veins with cross-veins. Lower glume apex caudate. Upper glume elliptic; 13–22 mm long; 1.5 length of adjacent fertile lemma; membranous; pallid; without keels; 8–9 -veined. Upper glume lateral veins with cross-veins. Upper glume apex caudate.

FLORETS Fertile florets female. Fertile lemma lanceolate, or ovate; dorsally compressed; 8.5–10.3 mm long; indurate; pallid and mid-green; mottled with last colour; shiny; without keel; 5 -veined. Lemma surface pubescent; hairy above and below. Lemma margins pubescent; hairy below. Lemma apex apiculate. Palea lanceolate; indurate; 9–10 -veined. Palea surface pubescent; hairy on back; hairy above.

FLOWER Lodicules 3; 1.1–1.2 mm long; membranous. Anthers 3; 1.9–2 mm long. Stigmas 2.

MALE Male spikelets distinct from female; 1 flowered; linear, or lanceolate; 3.2–6.4 mm long. Male spikelet glumes absent. Male spikelet lemma 3 -veined; awned; with 1 mm long awn.

DISTRIBUTION South America: Mesoamericana.

NOTES Olyreae. Soderstrom.

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