242 THE i'asmanian flora. 



eicept a short base. Spikelets single or many terminal, bnt thrust aside by a 

 leaf-like bract, never continuous with the stem, as in Seleocharis. 

 The genus is large, and found in all parts of the world, 

 i. Spikelets nearly always solitary... 

 Spikelets usually few or many ... 

 ii. Spikelets 2-3 lines long ... 



Spikelets often less than 1 line ... 

 iii. Nuts usually granular, and the outer suri 

 convex ... ' 

 Nut flat and shining 

 iv. Plant usually submerged. Spikelet narrow 



Terrestrial. Spikelet relatively broad ... 

 V. Leaves well developed. Nut acutely ang 

 smooth ... 

 Leaves reduced to sheaths 

 vi. Nut obtusely angled to nearly globose ... 



Nut longitudinally striate... 

 vii. Spikelets 2-3 lines, few ... 



Spikelets in a dense spherical head 

 Spikelets 4-9 lines... 

 viii. Glumes pale or mostly so . . . 

 Glumes dark purple 

 ix. Spikelets few, sessile 



Spikelets few, shortly stalked 

 Spikelets many, stalked ... 



1. S.. PLTJiTANS, Linn. Small, tufted or elongated, 

 alternate, mostly shorter than the stems. Spikelets solitary, terminal. Bracts 

 often very small, l|-2 lines long. Glumes about 6, the lowest longer than the 

 others, often as long as the spikelet. Stamens 3. Nut broad, smooth, .biconvex. 

 Isotefh fluitans, R. Br. 



Common in still fresh water. Throughout extra- tropical Australia and 

 temperate districts of both Hemispheres. 



Y&v. terrestrii!,-F. Y-IA. Developed on soil. Stems obsolete. Leaves and 

 scapes tufted. Spikelets rather larger, and with more flowers than in 

 the type. 



2. S. CKASSluscTJLTJg, Hook. Plant tufted at the nodes of a creeping rhizome. 

 Leaves flat, mostly'2 or 3 inches long, from f-lj line wide. Stems about as long 

 or longer than the leaves. Spikelet .solitary, terminal, about 3 lines long, the 

 subtending bract short. Glumes numerous, obtuse to nearly acute, obscurely 

 striate. Style-branches 2. Nut flat, pale, smooth, the back convex, the margin 

 generally flattened, but not always so. Isolepis rr'a.iHuKCvJus, B.. Br. 



Common on mountain-tops, near George's Bay, Circular Head, (fee, in pools ;. 

 also in Victoria and New South Wales. 



3. S. LENTICULARIS, Spvenq. Usually densely tufted. Leaves filiform, 1-2 inches 

 long, 3 or 4 to each stem at the base, and usually 1 above the base. Stems 

 slender, 1-3 inches long. Spikelet solitary, terminal, pale, about 2 lines long. 

 Bracts usually little longer. Glumes about 6, nearly equal. Stamens usually 2. 

 Nut biconvex, smooth, pale to flat on inner surface, polished and brown. 

 Isolepis lenticularis, R. Br. 



Common in swamps ; also in New South Wales. 



4. S. EiPAEins, Spreng. Densely tufted, with numerous filiform stems, 2-8 

 inches. Leaves normally reduced to sheathing bases. Spikelet usually solitary, 

 about i line long. Bract obsolete to f inch long, and then thrusting the spikelet 

 to one side. Glumes short, broad, obtuse, except the prominent midrib. 



