1768 CLII. CYPERACEiE. 



5. SCIRPUS, Linn. 



(From the Celtic for Rushes.) 



(Isolepia, R. Br. ; Malacoch»te^ Nees.) 

 Spikelets clustered, irregularly umbellate or rarely solitary, with several usually 

 many hermaphrodite flowers. Glumes imbricate all round the rhachis, alt 

 flowering or the lowest 1 rarely 2 empty. Hypogynous bristles none or.3 to 8^ 

 ciliate with minute reflexed hairs or flattened into plumose scales. Stamens 3, 2 

 or 1. Style deciduous, more or less divided into 2 or 3 filiform stigmatic- 

 branches, the base scarcely thickened, continuous with the nut and' remaining as 

 a small pbint or tubercle. Nut obovoid globular triquetrous or flat. — Small; 

 tufted annuals or if perennials sometimes tall and stout, the rhizomes often 

 creeping or sometimes slender long and floating. Leaves few at the base of the 

 stems or in tufts on the rhizome ; sometimes reduced to an appressed sheath with' 

 or without a short lamina, sometimes very long. Inflorescence sometimes- 

 terminal with 2 or more unequal long involucral bracts as in Cypenis, more 

 frequently more or less lateral with 1 erect involucral bract continuing the ^tem,. 

 in a few species the bract subtending the solitary terminal spikel^; is short and 

 glume-like. 



The genus is truly cosmopolitan, thriving alike within the tropics, and in Arctic, Antarctic 

 and Alpine regions, mostly in marshes, sometimes actually in water, rare in dry localities. 



I have followed Asa Gray and Bceckeler in reuniting Isolepis with Scirpus, for the sole character 

 by which they are distinguished, the absence of the bristles in the former, is variable in twq, or 

 three species, and in other 'instances separate species so closely allied that Bceckeler iia,s 

 united them as varieties. In the great majority of species however the character is so constant 

 and so frequently attended by a difference in inflorescence, that their is a convenience iu' 

 retaining the two groups at least as i^rtifieial sections. On the other hands, Nees' section or 

 genus Oneostylis, retained by Bcsckler in Scirpus, appears to me to be much more naturally 

 referred ' by Asa Gray to Fimhrittylis, of which it has the inflorescence, and the bulbous base 

 of the style, although often long persistent on the nut, is articulate with it, and often falls off' 

 from the perfectly ripe fruit. — Benth. 



^Eflx. I. XsolepiB. — No hypogynous brislles .(except very rarely in S. supinus). Small or 

 slender plants (except the last few species). 



Spikelets solitary. Style-branches 2. Nut biconvex. Stamens usually 3. 

 Spikelet narrow, few-flowered, 1 to 2 lines long. Stem or filiform rhizome 



often elongated and floating 1. 5. fltiitans. 



Spikelets solitary or clustered, small, (1 to 2 lines) ovoid or ovoid-oblong, 

 terminal or nearly so. Style-branches 3 rarely 2. 

 Stamens 3 rarely 2. Glumes prominently keeled. 

 Nut very small, obovoid, globular or 3-ribbed ; marked with longi- 

 tudinal furrows. Spikelets 1 to 3 . 2. S. setaceus. 



Stamens 1 or 2. Spikelets clustered. Glumes narrow with long recurved 



points. Nut very narrow 3. S. iqi(arrosus.. 



Stamen 1. Spikelets usually clustered, sometimes proliferous. Glumes 



broad. Nut acutely triquetrous 4. S. tnundatus 



Spikelets clustered, above 2 lines long, oblong or narrow. Style-branches 3. 



Spikelets in a terminal frequently proliferous cluster 5. S. prolifer. 



Spikelets in a lateral cluster. 

 Stems continuous, not thick: Spikelets few in the cluster. Nuts 



transversely ^^rinkled 6. S. supinus. 



Stems pithy with transverse septa inside. Spikelets in dense clusters. 



Nuts smooth 7. S. articulatns, 



Spikelets small and very numerous in a dense globular lateral cluster . 8. S. nodosus. . 



Section II. ^riBcir-pua.— Hypogynous bristles 3 to 8. Plants mostly tall and stout. 

 Spikelets in sessile lateral clusters. 



Stems terete. Style-branches 2. Nut flat 9. jS. dehilis. 



Stem acutely 3-angled. Style-branqhes 3. 



Spikelets many. Glumes entire 10. S. mncronatus.. 



Spikelets in a terminal or nearly terminal simple or compound irregular 

 umbel or cluster. 

 Involucral bracts very short, erect and rigid. Style-branches 2. 

 Bristles filiform, with short reflexed cilia . . , 11. 5. lacnstris. 



