Pentarrhaphis scabra

HABIT Perennial; caespitose. Culms erect; 15–30 cm long. Leaves mostly basal. Ligule a fringe of hairs. Leaf-blades involute; 2–5 cm long; 1 mm wide; coriaceous; stiff. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 8–12; borne along a central axis; cuneate; 0.4–0.8 cm long; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Central inflorescence axis 4–5 cm long; tip filiform. Rhachis deciduous from axis; terminating in a barren extension; extension a forked bristle.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets sessile; 1 in the cluster.

STERILE SPIKELETS Companion sterile spikelets represented by awns; comprising 2 awns (hirsute); 4 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets cuneate; dorsally compressed; 4 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus bearded.

GLUMES Glumes dissimilar. Lower glume subulate; 8 mm long. Lower glume surface hispid. Upper glume subulate; 4 mm long. Upper glume surface hispid.

FLORETS Fertile lemma elliptic; 4 mm long; cartilaginous; without keel; 3 -veined. Lemma surface pubescent; hairy below. Lemma apex lobed; 3 -fid; with outer lobes shorter and with central lobe bidentate; incised 0.5 of lemma length; awned; 3 -awned. Principal lemma awn from a sinus; 4 mm long overall. Lateral lemma awns arising on margin of lemma; 4 mm long; subequal to principal. Palea 1 length of lemma. Palea keels scaberulous. Apical sterile florets 1 in number; barren; ovate; 3 mm long. Apical sterile lemmas pubescent (at base); lobed; 3 -fid; awned; 3 -awned. Apical sterile lemma awns 3–4 mm long.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Cynodonteae. Griffiths.

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