Arthraxon echinatus

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 20–60 cm long; rooting from lower nodes. Culm-nodes glabrous. Lateral branches ample. Leaf-sheaths 1–2.25 cm long; glabrous on surface, or pilose; with tubercle-based hairs. Ligule a ciliolate membrane. Leaf-blade base amplexicaul. Leaf-blades lanceolate, or ovate; 1.5–3.5 cm long; 5–12 mm wide; flaccid. Leaf-blade surface glabrous, or pubescent. Leaf-blade margins tuberculate-ciliate. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1–5; single, or paired, or digitate; 2–4 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes linear; 3.5–3.75 mm long.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; 0.6–0.75 mm long; villous.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas; lanceolate; 4–4.5 mm long; shorter than fertile. Companion sterile spikelet glumes keeled; scabrous. Companion sterile spikelet lemmas 2; enclosed by glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 5.5–6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus glabrous; base truncate; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; chartaceous; 2-keeled; 5 -veined. Lower glume surface convex; spinose; rough on veins. Lower glume apex acute. Upper glume lanceolate; chartaceous; 1-keeled; keeled above; 3 -veined. Upper glume margins ciliolate. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 2.5–3 mm long; hyaline; 0 -veined; without midvein; without lateral veins. Fertile lemma lanceolate; 4–5 mm long; hyaline; without keel; 1 -veined. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.2 way up back of lemma; geniculate; 10–12 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3; 2 mm long.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Asia-temperate: China. Asia-tropical: India.

NOTES Andropogoneae. Patunkar 1993.

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