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.

Polytoca

HABIT Annual (1), or perennial (1). Culms 30–100–150 cm long; with prop roots (1/1). Ligule a ciliolate membrane. Leaf-blades linear, or lanceolate (1).

INFLORESCENCE Monoecious; with male terminal and mixed axillary inflorescences. Synflorescence simple (1), or compound (1); fasciculate (1/1). Inflorescence composed of racemes; axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; herbaceous.

Racemes single, or digitate (1); bearing few fertile spikelets; bearing 3–6 fertile spikelets on each, or 7 fertile spikelets on each (1). Rhachis fragile at the nodes; flattened (1), or subterete (1). Rhachis internodes oblong (1), or clavate (1); bearing a sterile companion laterally. Rhachis internode tip cupuliform (1), or crateriform (1).

Sexes segregated; on unisexual branches (1), or bisexual branches; with male above, or below (1). 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 represented by single glumes; separately deciduous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets (1/1); 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 6–6.5–7 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 (1), or oblong (1); indurate; 2-keeled; winged on keel. Lower glume surface not waisted (1), or laterally waisted (1); without pits; pubescent (1), or villous (1). Lower glume apex entire, or erose (1); emarginate (1), or obtuse. Upper glume elliptic (1), or oblong (1); coriaceous; without keels (1/1); 7 -veined (1/1). Upper glume apex acuminate (1), or caudate (1).

FLORETS Basal sterile florets barren (1/1); without significant palea (1/1). Lemma of lower sterile floret oblong (1/1); cartilaginous (1/1); acuminate (1/1). Fertile florets female. Fertile lemma oblong; hyaline (1), or cartilaginous (1); without keel; wingless; 9 -veined (1/1). Lemma surface unwrinkled; without grooves. Lemma apex acuminate (1), or cuspidate (1). Palea 0.75 length of lemma; hyaline; 1 -veined (1/1); without keels.

FRUIT Caryopsis with adherent pericarp; square (1/1); flattened (1/1); concavo-convex (1/1). Hilum punctiform.

MALE Male inflorescence of subdigitate racemes. Male spikelets distinct from female; ovate (1/1). Male spikelet glumes 2; muticous (1), or awned (1).

DISTRIBUTION Temperate Asia (1), or Tropical Asia.

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