URTICEiE. 69 



The other 6 species, ciliare, N., cuspi datum, W., nvdi- 

 jlorum, L., obtusum, Muhl., paniculatum, L., viridijlorum, L., 

 resemble these, but scarcely need a particular description. Both 

 H. bracteosum and H. cuspidatum have a little of that spontane- 

 ous motion of the leaves, for which H. gyrans, from the Ganges, 

 is so wonderfully distinguished, and for which no cause has yet 

 been discovered. Is it not possible, that this undulating agitation 

 may be owing to the varying temperature or moisture, or both, of 

 slight currents or vibrations of the air ? Great sensibility to one 

 or both of these particulars, and especially to that of heat, might 

 produce the agitations of the leaves, sometimes in one part and 

 not in an adjacent one, as well as in parts more remote from each 

 other. Even confinement in a large glass case might not be able 

 to prevent altogether the action of very acute sensibility. This 

 action in our species is very small compared with that of the In- 

 dian plant, which is in almost constant agitation over more or less 

 of its leaves. 



ORDER 78. URTICEiE. Nettle Tribe. 



Flow 7 ers without a corolla, monoecious or dioecious, with a per- 

 sistent divided calyx, into which the stamens are inserted ; ovary 

 superior, simple ; fruit a simple dehiscent nut ; leaves alternate, 

 often covered with pungent hairs ; some are heroaceous. 



The fibres of the bark are often strong, and valuable for cor- 

 dage. Some are narcotic, and stupefying, and poisonous. The 

 plants are spread over all climates and countries ; some grow T in 

 dry, arid situations, and some in wet forests, and seem to love the 

 shade. It is not a very large family in this country. 



Urtica. L. 19. 4. Nettle. 



Named from its burning stings, as many species have a sting- 

 ing property. Nettle has the same origin as needle. 



U. dioica. L. Common Stinging Nettle. Well known ; 

 grows by roadsides in clusters, 2-4 feet high, erect, stiff, with 

 opposite, cordate leaves ; flowers minute, and without beauty. 

 The prickles are tubes, which, when pressed or struck upon the 



