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.

Diheteropogon

HABIT Annual (2), or perennial (2). Rhizomes absent (3), or short (1). Culms erect (1/1); slender (1/1); 15–61.62–150 cm long. Ligule an eciliate membrane (3), or a ciliolate membrane (1). Leaf-blades filiform (1), or linear.

INFLORESCENCE Synflorescence simple (3), or compound (2); scanty (2/2). Inflorescence composed of racemes; terminal (2), or terminal and axillary (3); subtended by an unspecialized leaf-sheath (2), or a spatheole (2). Spatheole lanceolate (2/2); herbaceous (2/2).

Racemes paired. Rhachis fragile at the nodes. Rhachis internodes linear (3), or clavate (2). Rhachis internode tip crateriform. Raceme-bases filiform (2), or linear (3).

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear (3), or clavate (1).

STERILE SPIKELETS Basal sterile spikelets well-developed.

Companion sterile spikelets well-developed; deciduous with the fertile. Companion sterile spikelet glumes muticous (2), or awned.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear (2), or lanceolate (2); subterete (1), or dorsally compressed; 5–7.875–15 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate (2), or linear (2); pubescent (1), or pilose (3); base pungent; inserted.

GLUMES Glumes firmer than fertile lemma. Lower glume linear (1), or lanceolate; coriaceous; 2-keeled. Lower glume intercarinal veins absent (3/3). Lower glume surface concave (1), or with a longitudinal median groove, or deeply depressed; without pits. Lower glume apex entire (3), or dentate (1); 2 -fid (1/1). Upper glume linear (1/3), or lanceolate (2/3); 3 -veined. Upper glume surface glabrous (3), or pubescent (1).

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic (1/1); hyaline; 0 -veined (1/3), or 2 -veined (2/3). Fertile lemma linear (2), or oblong (3); hyaline (3), or membranous (1); without keel; wingless; 3 -veined (3/3). Lemma surface unwrinkled; without grooves. Lemma margins eciliate (2), or ciliate (2). Lemma apex dentate (1), or lobed (3); 2 -fid; incised 0.2–0.34–0.66 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; bigeniculate. Column of lemma awn hispidulous (1), or puberulous (2), or pubescent (1), or hirtellous (1). Palea present (2), or absent or minute (3); hyaline (2/2); 2 -veined (2/2). Palea keels ciliolate (2/2).

FLOWER Anthers 3 (1/1).

DISTRIBUTION Africa.

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