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.

Acroceras macrum

HABIT Perennial. Rhizomes elongated. Culms decumbent; 20–100 cm long; rooting from lower nodes. Culm-nodes glabrous. Ligule a fringe of hairs. Leaf-blades linear; parallel-sided, or tapering towards tip; flat, or convolute; 3–16 cm long; 1–8 mm wide. Leaf-blade venation without cross veins. Leaf-blade surface glabrous, or pubescent.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1–5; borne along a central axis; appressed; unilateral; 2–8 cm long. Central inflorescence axis 5–25 cm long. Rhachis angular; glabrous on surface. Spikelet packing irregular.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels linear; angular; unequal; 4–6 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; subterete; 4–4.8 mm long; falling entire. Spikelet callus glabrous; base truncate.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.5–0.8 length of spikelet; herbaceous; without keels; keel-less except near apex; 3 -veined. Lower glume apex acute. Upper glume elliptic; 3.5–4.5 mm long; herbaceous; without keels; keel-less except near apex; 5 -veined. Upper glume apex laterally pinched.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; oblong; 1 length of fertile lemma; 1 length of spikelet; herbaceous; 5 -veined; laterally pinched at apex. Palea of lower sterile floret scabrous. Fertile lemma elliptic; dorsally compressed; 3.5–4.5 mm long; indurate; pallid. Lemma margins involute. Lemma apex apiculate; with a little green crest. Palea reflexed at apex; elliptic; involute; 1 length of lemma; indurate; 2 -veined; without keels.

FRUIT Disseminule comprising a spikelet.

DISTRIBUTION Africa: west-central tropical, northeast tropical, east tropical, southern tropical, and south. South America: northern South America.

NOTES Paniceae. FTEA.

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