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.

Trilobachne

HABIT Annual. Culms 100–250 cm long. Ligule an eciliate membrane. Leaf-blades lanceolate.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence, or with male and female spikelets in different inflorescences. Inflorescence composed of racemes; axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; herbaceous.

Racemes single; bearing few fertile spikelets; bearing 1–4 fertile spikelets on each. Rhachis fragile at the nodes; subterete. Rhachis internodes oblong; bearing a sterile companion laterally. Rhachis internode tip cupuliform.

Sexes segregated; on bisexual branches; with male above. Spikelets embracing internode; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Male spikelets sessile and pedicelled; 2 in a cluster. Pedicels fused to internode.

STERILE SPIKELETS Companion sterile spikelets well-developed; separately deciduous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 6–7 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base truncate; with central peg; attached transversely.

GLUMES Glumes exceeding apex of florets; firmer than fertile lemma. Lower glume elliptic; indurate; without keels; winged on margins. Lower glume surface without pits; pubescent. Lower glume apex lobed; 3 -fid; obtuse. Upper glume elliptic; coriaceous. Upper glume apex acuminate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; cartilaginous; acute. Fertile florets female. Fertile lemma oblong; hyaline; without keel; wingless. Lemma surface unwrinkled; without grooves. Lemma apex acute. Palea hyaline; without keels.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

MALE Male inflorescence of subdigitate racemes. Male spikelets distinct from female. Male spikelet glumes 2.

DISTRIBUTION Tropical Asia.

Please cite this publication as detailed in How to Cite Version: 27th January 2014.