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 amplectens

HABIT Annual. Culms decumbent; weak; 30–100 cm long; rooting from lower nodes. Ligule an eciliate membrane, or absent. Leaf-blade base cordate, or amplexicaul. Leaf-blades linear; 4–20 cm long; 3–10 mm wide. Leaf-blade venation without cross veins, or with obscure cross veins. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–6; borne along a central axis; distant; unilateral; 3–12 cm long. Central inflorescence axis 10–30 cm long. Rhachis angular; glabrous on surface. Spikelet packing lax; irregular.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels linear; angular; unequal; 1–3 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 4.5–6 mm long; falling entire. Spikelet callus glabrous; base truncate.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume lanceolate; 0.5–0.8 length of spikelet; herbaceous; without keels; keel-less except near apex; 3 -veined. Lower glume apex acuminate. Upper glume ovate; 4–5.5 mm long; herbaceous; 5 -veined. Upper glume apex laterally pinched.

FLORETS Basal sterile florets male, or barren; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of fertile lemma; 1 length of spikelet; herbaceous; 5 -veined; laterally pinched at apex. Fertile lemma oblong; dorsally compressed; 4–5.5 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.

FLOWER Anthers 3; 2 mm long.

FRUIT Caryopsis with adherent pericarp; oblong; dorsally compressed; plano-convex; pallid. Embryo 0.4–0.5 length of caryopsis. Hilum linear; 1 length of caryopsis. Disseminule comprising a spikelet.

DISTRIBUTION Africa: west tropical, west-central tropical, northeast tropical, and east tropical.

NOTES Paniceae. FTEA.

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