Axonopus hydrolithicus

HABIT Perennial; caespitose; clumped densely. Butt sheaths persistent and investing base of culm; with compacted dead sheaths. Culms erect; 45–78 cm long; 7–11 -noded. Culm-internodes hollow; distally glabrous. Culm-nodes brown; glabrous. Lateral branches lacking. Leaves basal and cauline. Leaf-sheaths wider than blade at the collar; without keel; striately veined; glabrous on surface; outer margin glabrous. Ligule a fringe of hairs; 0.5 mm long. Leaf-blades filiform; terete; 10–20 cm long; 0.5–1 mm wide. Leaf-blade surface grooved along midline; scaberulous; pilose; sparsely hairy.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary. Peduncle 6–21 cm long.

Racemes 1; single; straight, or arcuate; unilateral; 6.6–9.2 cm long. Rhachis broadly winged; membranous; folded longitudinally to embrace spikelets; 1.8–2.2 mm wide; glabrous on margins, or ciliate on margins; terminating in a barren extension; extension 5 mm long. Spikelet packing adaxial.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 2.3–3.1 mm long; falling entire.

GLUMES Glumes one the lower absent or obscure; reaching apex of florets; thinner than fertile lemma. Upper glume lanceolate; 2.3–3.1 mm long; 1 length of spikelet; hyaline; without keels; 2 -veined. Upper glume primary vein absent. Upper glume surface scabrous. Upper glume apex erose; acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret unlike other scales; lanceolate; 1.5–2 mm long; 0.66 length of spikelet; hyaline; 2 -veined; without midvein; distinctly veined; ciliate on margins; bearing hairs 1.5 mm long; acute; awned. Awn of lower sterile floret flexuous; 5–7 mm long. Fertile lemma oblong; dorsally compressed; 1.9–2.2 mm long; membranous; much thinner above; dark brown; without keel. Lemma margins flat. Lemma apex acute. Palea gaping; 1.8–2.2 mm long; 1 length of lemma; hyaline; 2 -veined. Palea apex dentate; 2 -fid.

FLOWER Lodicules 2; 0.1 mm long. Anthers 2; 1.3–1.7 mm long; purple. Stigmas 2; terminally exserted.

FRUIT Caryopsis with adherent pericarp; obovoid; 1–1.2 mm long. Embryo 0.4–0.5 length of caryopsis. Hilum punctiform, or elliptic.

DISTRIBUTION South America: Brazil.

NOTES Paniceae. Filguieras 1994.

ADDITIONAL CHARACTERS Sterile lemma 2-awned.

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