GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Pentarrhaphis polymorpha

HABIT Perennial; caespitose. Culms erect; 15–30 cm long. Ligule a fringe of hairs. Leaf-blades 5–10 cm long; 1 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–8; borne along a central axis; cuneate; 0.6–1 cm long; bearing few fertile spikelets; bearing 2 fertile spikelets on each. Central inflorescence axis 2 cm long; tip filiform (0.5–1mm, forked). Rhachis deciduous from axis; terminating in a barren extension; extension a forked bristle.

Spikelets in pairs. Fertile spikelets sessile; 2 in the cluster.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets cuneate; dorsally compressed; 5–6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus bearded.

GLUMES Glumes dissimilar. Lower glume subulate; 4 mm long. Lower glume surface hispid. Upper glume subulate; 5–6 mm long. Upper glume surface hispid.

FLORETS Fertile lemma elliptic; 3–4 mm long; cartilaginous; without keel; 3 -veined. Lemma lateral veins close to midvein. Lemma surface pilose. Lemma hairs 1 mm long. Lemma apex lobed; 3 -fid; with outer lobes shorter and with central lobe bidentate; incised 0.33 of lemma length; awned; 3 -awned. Principal lemma awn from a sinus; 3–4 mm long overall. Lateral lemma awns arising on margin of lemma; 3–4 mm long; subequal to principal. Palea 1 length of lemma. Palea apex dentate; 2 -fid; with excurrent keel veins. Apical sterile florets 1 in number; male; lanceolate; 2.5–3 mm long. Apical sterile lemmas awned; 3 -awned. Apical sterile lemma awns 3–4 mm long.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Mexico.

NOTES Cynodonteae. Griffiths.

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