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.

Arundinella thwaitesii

HABIT Annual. Culms erect; 43–70 cm long. Culm-nodes glabrous, or pubescent. Lateral branches lacking. Ligule an eciliate membrane. Leaf-blades 10–20 cm long; 3–6 mm wide; stiff. Leaf-blade surface glabrous; hairless except near base. Leaf-blade margins glabrous, or tuberculate-ciliate. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle; bearing juvenile spikelets at emergence.

Panicle open; elliptic; 9–18 cm long; 3–5 cm wide. Panicle axis smooth. Panicle branches smooth.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels glabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 3.25–3.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus glabrous; obtuse.

GLUMES Glumes persistent; dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume orbicular; 2 mm long; 0.66 length of upper glume; membranous; purple; 1-keeled; 3 -veined. Lower glume surface asperulous; rough on veins. Lower glume apex obtuse. Upper glume elliptic, or orbicular; 3 mm long; 1.3 length of adjacent fertile lemma; 1 length of spikelet; membranous; purple; 1-keeled; 5 -veined. Upper glume surface asperulous; rough on veins. Upper glume apex obtuse.

FLORETS Basal sterile florets male; with palea; persisting on inflorescence. Lemma of lower sterile floret similar to upper glume; ovate; 3 mm long; membranous; 1-keeled; 3 -veined; acute. Fertile lemma elliptic, or oblong; 2.25 mm long; coriaceous; pallid; without keel; 3 -veined. Lemma lateral veins obscure. Lemma surface asperulous. Lemma margins involute; interlocking with palea keels. Lemma apex entire; obtuse; muticous. Palea with auriculate flaps; coriaceous; 2 -veined. Palea surface asperulous.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 2.25 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Asia-tropical: India.

NOTES Arundinelleae. Bor 1993.

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