CYPERACEJS. (SEDGE FAMILY.) 495 



1. D. spatliaceum, Pers. Borders of ponds; common. July- 

 Scpt. 



4. IBE?IICARPHA, Nees. HEMICARPHA. 



Spikes many-flowered, ovoid, one or few in a lateral cluster, sessile. Scales 

 regularly imbricated in many ranks, ovate or obovate. Inner scale single be- 

 hind the flower, very thin, finally often adhering to or wrapped around the ob- 

 long or obovoid pointless naked achenium. Perianth none. Stamen 1. Style 

 2-cleft. Little tufted annuals resembling Scirpus, except as to the minute inner 

 scale, which is readily overlooked ; the naked culms with bristle-like leaves at 

 the base. (Name from JJI/M, half, and Kap<oy, straw or chaff, in allusion to the 

 single inner scalelet on one side of the flower.) 



1. II. Slibsquarrosa, Nees. Dwarf (l'-4'high); involucre 1 -leaved, 

 as if a continuation of the bristle-like culm, and usually with another minute 

 leaf; spikes 2-3 (2" long) ; scales brown, tipped with a short recurved point- 

 (Scirpus subsquarrosus, MM.) Sandy borders of ponds and rivers ; not rare, 

 often growing with Cyperus inflexus. July. Var. DRUMMOXDII (H. Drum- 

 mondii, Nees) is a form with single and pale or greenish heads. Illinois and 

 southward. 



5. EL.EOCIIARIS, R. Brown. SPIKE-RDSH. 



Spike single, terminating the naked culm, many - several-flowered. Scales 

 imbricated all round in many, rarely in 2 or 3, ranks. Perianth of 3 - 12 (com- 

 monly 6) bristles, usually rough or barbed downwards, rarely obsolete. Sta- 

 mens 3. Style 2 - 3-cleft, its bulbous base persistent as a tubercle, which is 

 jointed with the apex of the lenticular or obtusely triangular achenium. Leaf- 

 less, chiefly perennial, with tufted culms sheathed at the base, from matted or 

 creeping rootstocks. (Name from eXos, a marsh, and x a ^P m -> to deligld in ; being 

 marsh plants.) 



{ 1 . LIMN6CHLOA, Nees. Scales of the dense and terete many-flowered spUca 

 papery-coriaceous and rounded, with a scarious margin, pak : style 3-cleft : ache- 

 mum doubly convex, about equalling the bristles. 



* Culms large and stout, often thicker than the cylindrical spike: scales faintly many- 

 striate, and densely imbricated so as usually to form (Jive) distinct spiral rows : 

 sheaths at the base ojli.n nearly leaf-bearing. (LiiixocHLOA proper.) 



1. E. eqilisctoides, Torn Culm terete, knotted as if jointed by many 

 cross partitions (2 high, thick as a goosequill) ; achenium smooth, crowned with 

 a conical-beaked tubercle. Shallow water, Rhode Island (Olney), Michigan 

 (Houghton), Delaware, and southward. Spike 1' or more long. 



2. E. quadra II glllata, R. Brown. Culm even, sharply 4-angled (2- 

 4 high); achenium finely reticulated, crowned with a conical flattened distinct 

 tubercle. Penn., Michigan, and southward. 



* * Culms slender : spike ovate or oblong : scales tcith a midrib. 



3. E. tllbercillosa, R. Brown. Culms striate (8' -12' high); bristles 

 strongly barbed downward ; achenium triangular, ribbed and minutely reticulated, 



