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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.
Arthraxon lanceolatus
HABIT Annual. Stolons present. Culms decumbent; 20–80 cm long. Culm-nodes glabrous. Ligule an eciliate membrane. Leaf-blade base broadly rounded. Leaf-blades lanceolate; 1–5 cm long; 2–8 mm wide. Leaf-blade margins tuberculate-ciliate; hairy at base. Leaf-blade apex acuminate.
INFLORESCENCE Inflorescence composed of racemes.
Racemes 2–4; paired, or digitate; 2–5 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes linear; 2.5–3 mm long.
Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; 1–1.5 mm long; ciliate.
STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; 4–5 mm long; shorter than fertile. Companion sterile spikelet glumes keeled; 6–7 -veined. 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; 5–6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent; 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; 5–7 -veined. Lower glume lateral veins distinct. Lower glume surface flat; spinose; rough on flanks. Lower glume apex acute. Upper glume lanceolate; chartaceous; 1-keeled; keeled above; 3 -veined. Upper glume surface scabrous; rough at apex. Upper glume margins ciliate. Upper glume apex acute.
FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 2–3 mm long; hyaline; 2–3 -veined. Fertile lemma lanceolate; 4 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 5–6 mm long; glabrous. Palea absent or minute.
FLOWER Anthers 3; 1–2 mm long.
FRUIT Caryopsis with adherent pericarp.
DISTRIBUTION Africa: south. Asia-tropical: India and Indo-China.
NOTES Andropogoneae. Nair 1993.
Please cite this publication as detailed in How to Cite Version: 3rd February 2016.
