Arthraxon pusillus

HABIT Annual. Culms geniculately ascending; slender; 15–35 cm long. Culm-internodes distally glabrous. Ligule a ciliolate membrane. Leaf-blades lanceolate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–9; digitate; 0.5–2 cm long. Rhachis fragile at the nodes. Rhachis internodes filiform to linear.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels reduced to a stump.

STERILE SPIKELETS Companion sterile spikelets represented by barren pedicels.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 0.8–1.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base truncate; attached transversely.

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

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma oblong; hyaline; without keel; 1 -veined. Lemma apex acute; awned; 1 -awned. Principal lemma awn dorsal; arising 0.2 way up back of lemma; geniculate; 5–6 mm long overall; with twisted column. Palea absent or minute.

FLOWER Anthers 2; 0.2 mm long.

DISTRIBUTION Asia-temperate: Arabia.

NOTES Andropogoneae. Fl Arabia 2007.

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