Rhaphis villosula (Nees ex Steud.) Jacks.
Tufted perennial; culms slender, 50-150 cm high. Leaf-blades 10-30 cm long, 2-7 mm wide, rounded or slightly narrowed at the base. Inflorescence 8-25 cm long; racemes reduced to a single triad of 1 sessile and 2 pedicelled spikelets, rarely with 2-6 sessile spikelets (up to 10 in Australia). Sessile spikelet narrowly oblong, 2.4-3.3 mm long, scabrid, occasionally pubescent, acute; lower glume shallowly concave with 2 intercarinal nerves; awn 10-15 mm long. Pedicelled spikelet lanceolate, 2.2-3.5 mm long.
Fl. & Fr. Per.: May-September.
Type: Australia, Brown (K).
Distribution: Pakistan (Baluchistan, Punjab, N.W.F.P. & Kashmir); eastern Africa from Sudan to Mozambique; tropical Asia and Australia.
In Asia and Australia in particular this species is quite variable, mainly due to introgression from Bothriochloa bladhii, and DeWet (in Am. J. Bot. 54: 384-387. 1967) has distinguished four varieties. Two of these are restricted to Australia and New Guinea while the others are of wider distribution, both occurring in South-west Asia. The two Asian varieties may be distinguished as follows:
var. parviflorum: includes plants with 1-4 articulate racemes, very rarely as many as 6; robust or slender plants with glabrous to pilose leaves and culms. Sexually reproducing diploids (2n=20) and apomictic segmental allopolyploids (2n=40, 50, 60) are known.
var. “capilliflorum” (as Dichanthium parviflorum (R. Br.) DeWet var. capilliflorum (Steud.) DeWet & Harlan, based on Andropogon capilliflorum Steud.): includes plants with 3-5-articulate racemes, very rarely 2-3 but these scattered in inflorescences otherwise with 3-5-articulate racemes. Apomictic segmental allopolyploids with 2n=40, 50, 60.
These varieties can be distinguished chemically by their essential oils, but their morphological differences are far too vague for them to be maintained in this Flora.
Although at the diploid level Capillipedium parviflorum and Capillipedium assimile are genetically completely isolated (DeWet & Harlan in Taxon 19:339-340. 1970) they introgress at the tetraploid level.