Phragmites roxburghii (Kunth) Steud.
Perennial reed, with creeping rhizomes. Culms erect, up to 10m high. Leaf-blades 30-80 cm long and 12-40 nun wide, glabrous, rough to the touch beneath (at least in the upper half), the tips attenuate and stiff (occasionally almost smooth or with filiform tips). Panicle 30-50 cm long, 10-20 cm wide, the lowest node often many-branched in a whorl, the branches bare of spikelets for some distance from their base. Spikelets 9-12 mm long, the rhachilla-hairs 4-7 mm long, rather sparse; lower glume just over half as long as the upper; upper glume narrowly elliptic to very narrowly elliptic, 4-6 mm long, acute to subacute; lowest lemma very narrowly elliptic, 7.5-12 mm long; fertile lemmas very narrowly lanceolate, 85-11 mm long.
Fl. & Fr. Per.: April-November.
Type: India, Koenig (LD).
Distribution: Pakistan (Sind, Baluchistan, Punjab, N.W.F.P., Gilgit & Kashmir); tropical Africa, Polynesia, northern Australia and tropical Asia.
Phragmites karka occurs in swamps and beside streams. It is said to be poisonous to cattle (Duthie) but in any case it is far too course for fodder.
For most of their range these two species of Phragmites are allopatric. Phragmites austrails is a temperate species while Phragmites karka is tropical. Pakistan lies on the ecotone, and taxonomic problems are therefore considerable. It is probable that introgression occurs in this region and as a result determination of specimens is largely arbitrary. The measurements given above do not always apply and for the purposes of this Flora considerable importance is attached to the scabridity of the leaves.