Chionachne biaurita

HABIT Annual. Culms erect; robust; 40–50 cm long. Lateral branches ample. Leaf-sheaths loose; mostly shorter than adjacent culm internode; hispid; with tubercle-based hairs. Ligule a fringe of hairs. Leaf-blades 12–24 cm long; 5–10 mm wide; flaccid. Leaf-blade surface glabrous, or pilose; sparsely hairy; hairy adaxially. Leaf-blade margins scabrous.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence. Synflorescence compound; paniculate. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; 2 cm long; scarious.

Racemes 1; single; 1.5–2 cm long; bearing few fertile spikelets; bearing 4 fertile spikelets on each. Rhachis fragile at the nodes; subterete. Rhachis internodes linear; 0.66–1 length of fertile spikelet; bearing a sterile companion laterally. Rhachis internode tip transverse; cupuliform.

Sexes mixed; with 5 male spikelets per branch. Spikelets embracing internode; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Male spikelets sessile and pedicelled; 1 in a cluster (as companion), or 3 in a cluster (as terminal triad). Pedicels fused to internode; united wholly; filiform.

STERILE SPIKELETS Companion sterile spikelets represented by barren pedicels (the 2 lower pairs), or well-developed (above); male; lanceolate; 5 mm long; shorter than fertile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 7–7.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus square; 1.5 mm long; base truncate; with central peg; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; chartaceous; without keels; winged on margins; winged broadly; winged above. Lower glume surface asperulous; rough on flanks; not waisted; glabrous. Lower glume apex dentate; 2 -fid. Upper glume ovate; 4.5 mm long; chartaceous; 5–7 -veined. Upper glume apex acuminate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret ovate; 4.5 mm long; membranous; 3 -veined; scaberulous. Fertile florets female. Fertile lemma ovate; 4.5 mm long; hyaline; without keel. Palea linear; hyaline; without keels. Palea apex dentate; 2 -fid.

FLOWER Lodicules absent. Anthers 3; 3 mm long.

FRUIT Caryopsis with adherent pericarp; oblong; dorsally compressed; 2.5 mm long; pallid. Embryo 0.75 length of caryopsis. Hilum punctiform (and depressed).

MALE Male spikelets distinct from female; with pedicels fused to rhachis; lanceolate; 5 mm long. Male spikelet glumes 2.

DISTRIBUTION Asia-tropical: Malesia.

NOTES Andropogoneae. Hackel 1997.

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