6. Scirpus. CYPERACEAE. 93 



H. Involucral bract short, erect ; style -branches 2. 



Bristles filiform, scabrous S. lacuster 10. 



Bristles or scales flattish, plumose 8. litt oralis 11 



H. Involucral bracts spreading ; stem triangular ; style- 

 branches 3 8. marilimus 12 



1. S. fluitans-, L. Stems filiform,, weak, creeping, or floating; leaves linear, alternate 

 at the nodes ; spikelet solitary, terminal, ovoid, 3-4 mm. long, few-flowered, the lowest 

 glume longer than the others; stamens 3, sometimes 2 : nut broad, smooth, whitish, 

 plano-convex. — Isolepis fluitans, R. Br. 



In or near water, in southern districts. Summer. 



2. S. setaceus, L. Stems filiform, 3-15 cm. ; leafblades very short, filiform ; spikelets 

 1-3, usually lateral, 3-4 mm. long, the short involucral bract solitary and erect ; glumes 

 few, with a green keel and sides turning brown ; nut almost globular, whitish, ribbed 

 longitudinally and striate transversely. |-|- mm. long ; stamens 2-3. — Isolepis setacea, R. Br. 



Moist spots as far north as Flinders Range. Summer. 



3. S. cernuus, Vahl (1806). Resembles the preceding, but the stems are even weaker 

 and often curved ; spikelets usually solitary, sometimes 2-3, 2-4 mm. long, with a very 

 short erect, or longer spreading bract ; glumes thin, striate, brownish, acute ; stamens 

 2-3, or sometimes 1 only, especially in specimens with 2-3 spikelets ; nut f mm. long, 

 obovoid, trigonous, obtuse, but pointed at summit, minutely granular, finally almost 

 black and shining. — 8. riparius, Poir (1820) ; Isolepis riparia, R. Br. (1810). 



Common in southern districts near water. Summer. 



4. S. antarcticus, L. Usually a neat little tufted plant 3-6 cm. high, sometimes taller ; 

 leaves short linear ; spikelets 1-6, few-flowered, 3-4 mm. long, with an erect or spreading 

 bract longer than the cluster ; glumes boatshaped, stiff and shining, with a green keel, 

 the sides with curved nerves and a reddish -brown spot ; nut obovoid, trigonous, 1 mm. 

 long, finely granular, obtuse at summit, and sometimes with a minute blunt point, at first 

 yellow, becoming brown, not shining ; stamens 2-3. — S. cartilagineus, Poir ; Isolepis 

 cartilaginea, R. Br. 



Throughout the State, at least as far as the northern part of the Flinders Range. Sept. - 

 Dec. 



5. S. stellatus, C. B. Clarke. Stems, leaves, and bract like the preceding, but the spike- 

 lets are in clusters of 4-8, the glumes greenish with a short spreading point ; nut obovoid, 

 triquetrous, f mm. long, with a conical point, minutely granular, black, shining. 



Naracoorte ; Penola. Summer. 



6. S. inundatus (R. Br.), Poir. Stems usually long and rather stout, but flaccid; leaf- 

 sheath basal, with a short point ; spikelets 4-6 mm. long, usually 3-12 in a cluster, which 

 is often proliferous ; glumes rather numerous, with a green keel and striate brown sides ; 

 stamen 1 ; nut 1 J mm. long, trigonous or plano-convex, obtuse but pointed, white, smooth 

 and shining. 



In marshes or beside water in the southern districts and South-East. Summer. 



7. S. supinus, L. Stems tufted, spreading or ascending ; basal leafsheaths terminating 

 in a short blade ; spikelets 1-6 together, 5-10 mm. long, much surpassed by the erect 

 involucral bract ; glumes acute, keeled, deciduous ; stamens 2-3 ; nut obtusely trigonous 

 (plano-convex), obtuse at summit, finally black, strongly transversely wrinkled, usually 

 with 5-6 short hypogynous bristles at base. — Isolepis supina, R. Br. 



Near Finke River, and therefore probably exists in our Far North. 



8. S. nodosus, Rottb. Rootstock creeping; stems erect, subcompressed, 50-100 cm. 

 high, stout and rigid by the sea, more slender inland ; leaves reduced to sheathing bases ; 

 spikelets brown, clustered in a dense ovoid or globular head, the short stiff involucral 

 bract continuing the stem ; glumes obtuse ; nut smooth, plano-convex, about \ as long 

 as the glume. — Isolepis nodosa, R. Br. 



Sandhills near sea, and inland near water. Summer. 



9. S. americanus, Pers. (1805). Rootstock creeping; stems rather stout, triquetrous; 

 leaves chiefly basal, plano-convex ; spikelets brown, 6-10 mm. long, ovoid, usually 3-4 in 

 a lateral cluster, surpassed by the erect involucral bract ; glumes notched and mucronate ; 

 style -branches 3 ; nut plano-convex, smooth ; hypogynous bristles usually 6. — 8. pungens, 

 Vahl (1806). 



In fresh and brackish water throughout the State. Oct. -Mar. 



10. S. lacuster, L. Tall plant, with stout cylindrical stems ; leaves almost reduced to 

 sheathing bases ; spikelets brown, 5-10 mm. long, numerous in an irregular umbel, which 

 is shorter than the erect involucral bract ; glumes keeled, mucronate, sometimes notched ; 

 style -branches usually 2 ; nut plano-convex, smooth, shining ; hypogynous bristles 

 usually 6, as long as or longer than the nut, with reflexed teeth. 



In fresh or brackish water throughout the State. Oct. -Mar. 



