CTPERACEAE 



337 



Obs. This is a great pest, where it gets possession of the soil, 

 and requires prompt attention, for it multiplies rapidly. It is, how- 

 ever, not quite so bad as the C. Hydra, of the South. Although 

 prevalent North and South of us, I think this C. repens is a doubt- 

 ful native, of our County, as I never observed it, until within a 

 few years. It is now becoming rather alarmingly abundant, in 

 some' localities. 



5. C. filiculniis, Vahl. Culms slender and wiry; spikelets sub- 

 terete, clustered in a dense head. 



C. mariscoides. Ell. $ Fl. Cestr. ed. 2. p. 16. 

 THREAD-CULLED CYPERUS. 



Perennial; culms 6 to 12 inches long, reclining, tuberous at base. Leaves 

 shorter than the culm, keeled. Heads of spikelete 1 to 4,-^rone sessile, the others 

 on peduncles, or rays, 1 to 2 inches long ; spikelets 3- to 7- or 8-flowered. 

 Hjb. Old fields; slaty hills: frequent. Fl. Aug. Fr. Sept. 



2. Spikelets terete, linear, few-flowered', styles trifid ; stamens 3. 



6. C. OVUl&ris, Torrey. Spikeleis thickish, in a globose or oval 

 head, spreading, the lower ones finally reflexed ; sheaths of the 

 peduncles obtuse. 



Mariscus ovularis. Vahl. $ Fl. Ce&tr. ed. 2. $. 16. 

 EGG-SHAPED CYPERUS. 



Perennial. Culms 6 to 18 inches high, acutely triquetrous. Leaves shorter than 

 the culm. Heads 3 to 5 (sometimes but 1), about an inch in diameter, the middle 

 one sessile, the rest on peduncles % of an Inch to 3 inches in length ; spihekts 

 numerous, 2- to 4-flowered, often perfecting but 1 afcene. 

 Hob. ry, slaty or rocky hills : not common. Fl. Aug. Fr. Sept. 



7. C. retrofrctns, Torrey. Spikelets slender, in. an obovoid- 

 oblong head, all becoming reflexed; sheaths of the peduncles 

 bicuspidate. 



Mariscus retrofractus. Vahl. $ Fl. Cestr. ed, 2. p. 592. 

 BACKWARD-BENT CYPERUS. 



Perennial. Culms 1 to 2 feet high, obtusely triquetrous. Leaves about half 

 the length of the culm. Heads several, % an i nc h to qear .an inch long, on pedun- 

 cles 1 to 3 or 4 inches in lengthy tpiJtdets numerous, subulate, 1- or 2-flowered in 

 the middle, the uppermost ones usually spreading, the others more or less 

 reflexftd. 

 Hob. Hills, near Pugh-town: rare. FL Aug. Fr. Spt. 



459. DUMCH'IUM, Richard. 



[Derivation of the name not ascertained.] 



Spikelets compressed, linear, sessite, distkihously arranged in axillary 

 pedunculate spikes emerging from the sheaths of the leaves. Feri- 

 gynium of 6 to 9 retrorsely hispid bristles. Style long, bifid. Akene 

 linear-oblong, compressed. Perennial: culm simple, terete, nodose 

 and leafy to the summit. 



1, D. spatbftceuin, Pert. Leaves lance-linear, flat, short, 

 nearly equal, pointing in three directions; spikelets 5- to 9-flowered, 

 spreading. 



SPATHACBOUS DULICIIIUM. Sheathed Galingale. 



22 



