408 On some Grasses and Sedges from the East Coast ofDemerara. 



calities. It grows in Demerara on savannahs near trenches, and 

 is considered a great nuisance upon the pasturage. 



Cyperus rotvndus, Linn. ; Kunth, /. c. ii. 58. 

 C. Hydra, Meyer, I. c. 31. 



C. hexastachyus , Rottb. var. umbella laxa, radiis longis tri-tetra- 

 stachyis. 



Nut-grass. 



This is of all Cyperaceous plants the most universally distri- 

 buted, and the one which is most injurious to cultivation. It 

 requires unwearied care to eradicate it where it has once shown 

 itself. The round tubercles of its roots increase rapidly in num- 

 ber, each of which forms hereafter an individual plant if left in 

 the ground. Numerous fibres shoot from the base of the stem, 

 which descend where it finds a fertile soil from ten to twelve 

 inches into the ground, almost every one of which produces a 

 small tuber, from which spring horizontal fibres in every direc- 

 tion, forming additional tubers at a distance of six to ten inches 

 asunder. From each of the tubers rises a stem upwards which 

 becomes ultimately an individual plant, and which in its turn 

 throws out lateral fibres like the parent plant. In that manner 

 a single plant soon increases and spreads over the ground in a 

 short time. If a spot of a couple of square feet is dug up where 

 the nut-grass has been propagated, the interlacing of the roots 

 affords a most remarkable appearance, and the great number of 

 fibres resemble an elaborated network. The only means of eradi- 

 cating it with success where it has spread over cultivated ground, 

 is to dig up the soil repeatedly and to destroy the tubers by 

 burning them. Those which remain in the ground no doubt 

 will sprout, but by being exposed to the light the young shoots 

 bleach and perish, and the power of the tubers to reproduce new 

 shoots becomes ultimately exhausted. Almost every colony has its 

 own account how this great scourge to cultivation was introduced. 

 It is related in Barbados that the nut-grass was first brought 

 there in a pot of flowers sent to a Mr. Lillington in St. Thomas's 

 parish, and the earth being turned out of it the tuber took root, 

 and spreading over the adjacent fields it ultimately propagated 

 over the whole island. Such cases explain the otherwise almost 

 incredible distribution of a single species over the whole ha- 

 bitable world. As localities where the nut- grass has been found 

 growing, I will name England, France, Italy, Virginia, Carolina, 

 the West Indies, Mexico and South America, Ceylon, Bourbon, 

 Mauritius, East Indies, the Philippine Islands, the Marianas, New 

 Holland, China, Java, Guinea, Teneriffe, Egypt, Algiers, Arabia, 

 Caucasus ; indeed this list proves satisfactorily that it has spread 

 over the whole world ; but it deserves particularly to be men- 



