Digitaria nuda Schumach.

Beskr. Guin. Pl. 65 (1827).- Type: Thonning 367, Ghana (holo- C).

Panicum diamesum Steud., Syn. Pl. Glum. 1: 42 (1854).- Type: Leprieur s.n., Senegal (holo- P,iso- L);

Digitaria diamesa (Steud.) A. Chev., Rev. Int. Bot. Appl. Agric. Trop. 27: 284 (1947);

Digitaria nuda ssp. senegalensis Henr., Monogr. Digitaria: 831 (1950).

Regional litterature: Ghana grasses: 138 (1977); FTEA Gramineae: 654 (1982); Gram. Togo: 198 (1983); Gram. Cameroun: 325 (1992); Fl. Ethiopia & Eritrea 7: 256, fig (1995); Pl Pl. Mauritanie: 301 (1998); Poac. Niger: 451, fig. (1999); Fl. Bénin: 199 (2006); Pl. Vasc. Guiné-Bissau: 165 (2006); Fl. Guinea Bissau: 136 (2008);  Fl. Chad (2013); Sudan & S Sudan: 126 (2015).

Description:

* Annual of 0.15-1 m high. Culms decumbent at the base and geniculately ascending. Leaves linear, 2-20 cm long and 3-10 mm wide.

* Inflorescence digitate (axis up to 2 cm long in robust specimens) of 2-20 racemes. Racemes slender, straight, 4-20 cm long, with or without sparse white hairs, the spikelets binate and overlapping by about 2/3 of their lenth on a winged rhachis with triquetrous midrib.

* Spikelets narrowly elliptic, 1.7-2.5 mm long, sharply acute. Lower glume wanting or inconspicuous; upper glume 2/3-3/4 as long as spikelet, 3-nerved. Lower lemma as long as the spikelet, 7-nerved, the nerves smooth and evenly spaced (occasionally the pedicelled spikelet with a wide interspace flanking the midnerve) appressed puberulous to silky pubescent, often encompassed by a ciliate frill. Fruit ellipsoid, grey to light or grayish brown.

Distribution West Africa: Cape Verde, Guinea Bissau, Ghana, Togo, Benin, Niger, Chad, Sudan, South Sudan

Distribution world-wide: Ethiopia, Uganda, and Burundi, E and southern Africa, SE Asia, Americas.

Note: Very similar to D. ciliaris, but with slender racemes, shorter spikelets and obsolete lower glume. D. nuda is the common African species, whereas D. ciliaris is infrequent. The slender racemes are shared with D. horizontalis but this species has an definit central axis and a short upper glume (1/3-1/2 spikelet length).

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