Themeda polycephala Veldk., 2016

Veldkamp, J. F., 2016, A revision of Themeda (Gramineae) in Malesia with a new species from Laos, Blumea 61 (1), pp. 29-40 : 37-38

Themeda polycephala Veldk. , sp. nov.

Type. Poilane 28428 (holo L; E, K, P) .

Plants perennial. Culms c. 2 m long, solitary. Nodes glabrous. Ligule 1–1.7 mm long, margin ciliolate. Leaves 42–65 cm by 7–10 mm. Uppermost spatheoles glabrous. Peduncle 7–10 mm long, c. 1/2 times as long as the spatheole, white hairy. Capitules bi- or ternate, reflexed, long-persistent. Involucral spikelets conspicuous, pairs unequally inserted, male; lower glumes linear-lanceolate, 6–9 by 1–1.4 mm, acutish, herbaceous, 9-nerved, glabrous, keels distally setose; upper glumes 3-nerved. Fertile spikelets 2, 6.5–7 mm long (incl. callus), callus 1.5–2 mm long, pilose, hairs whitish, c. 2 mm long; lower glumes yellowish, apex truncate, glabrous, keels distally setose. Awn well-developed, perfect, 35–42 mm long, column 21–23 mm long (i.s.), geniculate, setulose, hairs white (i.s.). Anthers 2–3 mm long, purple i.s. Pedicel laterally setose. Pedicelled spikelets 4, male, 6.5–7 mm long, lower glumes apex acute to aristulate (arista up to 2 mm long), glabrous, keels distally setulose.

Distribution — Only known from the type: Laos, Champassak Prov., 55 km from Pakson(g), at Tateng, Plateau des Boloven(s), 13 Nov. 1938.

Habitat — Not recorded. The plateau is at 1000–1200 m altitude.

Note — This is a most curious species, especially because of the paired to ternate, reflexed spikelets at the end of the peduncle, unique in the genus. Also, the distally setose keels of the glumes have not been seen elsewhere.