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 tonkinense

HABIT Perennial. Culms decumbent, or rambling; 50–100 cm long; rooting from lower nodes. Culm-nodes pubescent. Leaf-sheaths 4–6 cm long; outer margin hairy. Ligule a ciliolate membrane. Leaf-blade base cordate. Leaf-blades lanceolate; 5–20 cm long; 5–20 mm wide. Leaf-blade surface scaberulous; glabrous. Leaf-blade margins cartilaginous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 5–10; borne along a central axis; unilateral; 3–11 cm long. Central inflorescence axis 8–15 cm long. Rhachis angular. Spikelet packing distant; irregular.

Spikelets ascending; in pairs. Fertile spikelets sessile and pedicelled; 1 in the cluster, or 2 in the cluster. Pedicels linear; angular; unequal; 2–10 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 4.5–5.5 mm long; falling entire. Spikelet callus glabrous; base truncate.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; clasping; 2.8–3.8 mm long; 0.9 length of spikelet; herbaceous; without keels; 5(–7) -veined. Lower glume apex acute. Upper glume elliptic; 4.2 mm long; 0.8–0.9 length of spikelet; 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; elliptic; 4.5–5.5 mm long; 1 length of spikelet; herbaceous; 5 -veined; laterally pinched at apex. Fertile lemma elliptic; dorsally compressed; 4 mm long; indurate; pallid. Lemma surface striate. Lemma margins involute. Lemma apex acute; with a little green crest. Palea reflexed at apex; elliptic; involute; 1 length of lemma; indurate; 2 -veined.

FLOWER Anthers 3; 2 mm long.

FRUIT Disseminule comprising a spikelet.

DISTRIBUTION Asia-temperate: China. Asia-tropical: India, Indo-China, and Malesia.

NOTES Paniceae. Gilliland.

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