PoTAMOrETLA, R. Br. 



Spikrlets laterally slightly compressed, on short or rather long pedicels, 

 panicled ; rhachilla jointed above the rudimentary basal glumes. Florets 3 ; lower 

 2 reduced to minute empty valves, uppermost hermaphrodite or imisexual with the 

 organs of the other sex reduced. 



Glumes reduced to very minute rounded or truncate scales, or to an obscure, 

 entire or bilobed hyaline rim. Empty valves very small, hyaline, nerveless, 

 subulate or elliptic and rounded or lobed ; fertile valve membranous, 5-nerved, 

 awnless, nerves raised, sometimes slightly winged. Pale 3-nerved ; otherwise 

 similar to the fertile valve. Lodicules 2, finely nerved. Stamens 6. Styles 

 distinct ; stigmas feathery. Grain obovate, compressed, crowned by the thickened 

 bases of the styles, enclosed by the unaltered glume and pale, free. 



Rather tall aquatic grasses, blades flat ; ligules membranous ; panicle effuse or 

 contracted. 



Species 3, 1 In South Africa, 1 in Madagascar, and I in New South Wales. 



PLATE 444. 



PoTAMOPHiLA PREHENSTLis, Benth. (Fl. Cap., Vol. Vir., p. 659). 



Nat. Order Graminese. 



Stems several feet high, branched, many-noded, slightly compressed or terete, 

 glabrous, smooth ; internodes up to 4 inches long ; branches spreading at a right 

 angle or almost so ; leaf-sheaths rather tight, shorter than or as long as the inter- 

 nodes, slightly compressed and more or less keeled, strongly striate, scabrid in the 

 uppermost part of the keel, hairy near the mouth or glabrous, except the sometimes 

 minutely villous nodes ; ligule membranous, oblong or truncate, ^ to 1 line long, 

 pubescent ; blades linear-lanceolate from a very short contracted base, acute, 3 to 

 5 inches by 3 to 6 lines, flat, flaccid, glaucous, sparingly hairy and minutely scabrid 

 on both sides, margins and midrib very rough from minute reversed spines ; 

 primary nerves 3 to 4 on each side. 



Panicle terminal, 4 to 6 inches long, open, very lax, rigid ; branches spreading, 

 fine, up to 4 inches long, the lowest usually paired, sparingly branched, compressed 

 and angular, scaberulous or smooth below, branchlets 2-3-spiculate ; pedicels 1 to 

 1 lines long. 



Spikelets lanceolate-oblong, acute, 3 to 4 lines long, slightly twisted, pallid. 



Glumes extremely minute truncate hyaline scales. Valves, empty one 

 subulate, \to\ line long, nerveless ; fertile valve tightly clasping the similar pale 

 with the inflexed margins, nsrves raised, slightly winged, scaberulous. Lodicules 

 ovate ; anthers 3 lines long ; styles \ line long ; stigma exserted near the base of 

 the valve, 1 to 1 J line long. Grain unknown. 



EdbitSit : Natal. Near the mouth of the Umzimkulu River, in copses and 

 woods, Drege; Umbilo waterfall, Rehmann 8156; Umpumulo, to 2000 feet, 

 common in bush, Buchanan 288 ; Inanda, Wood 1305. 



Drawn from Buchanan's 288. 



Fig 1, A glume ; 2 and 3, empty valves ; 4, fertile valve ; 5, pale ; 6, pistil, stamens 

 and lodicules. All enlarged. 



