Hyparrhenia bracteata

HABIT Perennial; caespitose. Butt sheaths woolly. Culms erect; 60–250 cm long. Culm-internodes distally glabrous, or hirsute (below nodes). Leaves cauline. Leaf-sheaths glabrous on surface, or hirsute. Ligule an eciliate membrane; 1–2 mm long. Leaf-blades 30–60 cm long; 2–4 mm wide; stiff; glaucous. Leaf-blade surface pubescent; hairy abaxially. Leaf-blade margins scabrous.

INFLORESCENCE Synflorescence compound; globose; 20–60 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; 2–3 cm long; membranous; glabrous, or pilose. Peduncle 1.5–2.5 cm long; pilose above (yellow hairs).

Racemes 2; paired; deflexed; 0.5–1.5 cm long; bearing few fertile spikelets; bearing 1–2 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes linear. Rhachis internode tip oblique; flat. Raceme-bases linear, or flattened; unequal (the longer measured); 1.5–2 mm long; stiffly setose; extended into an oblong appendage; with 1–2.5 mm long appendage.

Spikelets appressed; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; flattened; ciliate; tip oblique; without appendage.

STERILE SPIKELETS Basal sterile spikelets well-developed; on lower raceme 2 in number; 0 in upper raceme; lanceolate; 4–7 mm long; equalling fertile. Basal sterile spikelet glumes glabrous; scabrous on margins; lower glume muticous.

Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 4–6(–7) mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; glabrous; acute; muticous, or mucronate. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear, or oblong; dorsally compressed; 4–6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 1 mm long; pubescent; base acute; attached obliquely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; coriaceous; without keels; keel-less except near apex. Lower glume surface grooved on either side of midvein; glabrous. Lower glume apex dentate; 2 -fid. Upper glume linear; coriaceous; without keels.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of fertile lemma; hyaline; 2 -veined. Fertile lemma linear; membranous; without keel; 1 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10–25 mm long overall; with twisted column. Column of lemma awn pubescent. Palea absent or minute.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3. Stigmas 2.

FRUIT Caryopsis 3 mm long.

DISTRIBUTION Africa: west tropical, west-central tropical, east tropical, and southern tropical. Asia-tropical: Indo-China and Papuasia. North America: Mexico. South America: Mesoamericana, northern South America, western South America, Brazil, and southern South America.

NOTES Andropogoneae. WDC.

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