GrassBase - The Online World Grass Flora

Descriptions

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

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

Panicum brachystachyum

HABIT Perennial. Culms erect; 18–35 cm long. Culm-internodes terete; distally pilose. Culm-nodes pallid; glabrous, or pubescent. Leaf-sheaths pilose; outer margin hairy. Leaf-sheath auricles erect. Ligule a ciliate membrane; 0.3–0.4 mm long. Leaf-blade base simple, or cordate. Leaf-blades lanceolate; flat, or involute; 3–4.5 cm long; 2–3 mm wide. Leaf-blade midrib indistinct. Leaf-blade margins scabrous; ciliate. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle hispid above.

Racemes 2–4; borne along a central axis; unilateral; 1–4 cm long. Central inflorescence axis flattened; hispid. Rhachis angular; glabrous on surface, or hirsute on surface; scabrous on margins.

Spikelets in pairs. Fertile spikelets pedicelled. Pedicels unequal; ciliate.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 4.9–5.2 mm long; 3.5 mm wide; falling entire.

GLUMES Glumes similar; reaching apex of florets; thinner than fertile lemma; gaping. Lower glume ovate; 2.8–3 mm long; 0.33–0.5 length of spikelet; membranous; without keels; 1–3 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent, or obscure. Lower glume surface pilose; with tubercle-based hairs. Lower glume apex acuminate. Upper glume ovate; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume surface pilose; with tubercle-based hairs. Upper glume apex acute, or acuminate.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; much thinner on margins; 3–5 -veined; pilose; with tubercle-based hairs; acute, or acuminate. Palea of lower sterile floret 3.9–4.5 mm long; pilose; adorned on flanks. Fertile lemma lanceolate; dorsally compressed; 4–4.4 mm long; 1.2 mm wide; cartilaginous; pallid, or yellow; keeled; lightly keeled; 3–5 -veined. Lemma margins involute. Lemma apex acute, or acuminate. Palea involute; indurate.

FLOWER Lodicules 2; cuneate; 0.5 mm long. Anthers 3; 3.2 mm long; purple.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Brazil.

NOTES Paniceae. Zuloaga 1996.

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