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.

Arthraxon microphyllus

HABIT Annual. Culms rambling; slender; 15–30 cm long. Culm-nodes pubescent. Leaf-sheaths glabrous on surface, or pilose; with tubercle-based hairs. Ligule a ciliolate membrane; 0.4–2.5 mm long. Leaf-blade base broadly rounded. Leaf-blades lanceolate, or ovate; 0.3–1.7 cm long; 1–4 mm wide. Leaf-blade surface pilose; hairy on both sides; with tubercle-based hairs. Leaf-blade margins tuberculate-ciliate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle 1.7–9 cm long; glabrous.

Racemes 1–3; single, or paired, or digitate; 2.8–3.9 cm long. Rhachis fragile at the nodes; with scattered hairs, or pubescent on surface. Rhachis internodes filiform; 1.2–2.4 mm long.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; 1.6–1.9 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets represented by single glumes; linear; 1.9–2.2 mm long; shorter than fertile. Companion sterile spikelet glumes 6 -veined; scaberulous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 2.8–3.9 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent; base truncate; attached transversely. Spikelet callus hairs 0.2–0.5 mm long.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; chartaceous; without keels; 6–7 -veined. Lower glume surface scabrous; rough above and on veins. Upper glume lanceolate; chartaceous; 1-keeled; keeled above; 3 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 1.6–2.1 mm long; hyaline; 0 -veined; without midvein; without lateral veins. Fertile lemma lanceolate; 1.7–2.1 mm long; hyaline; without keel; 1 -veined. Lemma apex acute; awned; 1 -awned. Principal lemma awn dorsal; arising 0.2 way up back of lemma; geniculate; 7–11 mm long overall; with twisted column. Column of lemma awn 3.5–4.5 mm long; glabrous. Palea absent or minute.

FLOWER Anthers 2; 0.6 mm long.

FRUIT Caryopsis with adherent pericarp.

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

NOTES Andropogoneae. Welzen 1993.

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