70 PLANTS OF MASSACHUSETTS. 



flesh, throw out an acrid liquor, which produces the stinging 

 effects. Some of the Indian species produce far more painful 

 effects than those of this country. Widely spread over Europe. 



U. Canadensis. L. Large Stinging Nettle. So strong are 

 the fibres of the bark, that Mr. Whitlow proposed its culture as a 

 substitute for hemp ; sometimes grows 6 feet high, large, strong, 

 very hispid, and stinging. 



U. urens. L. Dwarf Stinger. A small stinging nettle, less 

 than 2 feet high, with opposite, elliptic leaves, acutely serrate ; 

 probably introduced from Europe. 



U. procera. Muhl. Not of much consequence. 



U. pumila. L. Stingless Nettle. Grows in moist and shady 

 places, often about houses ; stem a foot high, round, smooth, 

 fleshy, nearly pellucid, somewhat procumbent, and resembles a 

 long worm ; flowers monoecious, in axillary racemes or heads. 



BCEHMERIA. W. 19. 4. 



B. cylindrica. W. Taken from Urtica by Willdenow ; stem 

 2-4 feet high, erect, round, channelled, somewhat hairy, flowers 

 in long, axillary" cylindrical spikes, with leaves on petioles, and 

 3-nerved ; grows about fences in dry or damp soils ; blossoms in 

 June to August. 



Parietaria. L. 19. 4. 



P. Pennsylvania. Muhl. Pellitory. Stem about a foot high, 

 simple, with oblong-lanceolate leaves, veiny, and with opake dots ; 

 flowers in axillary clusters ; June, in rocky soils. On Sugar 

 Loaf, Deerfield. Hitchcock. 



Cannabis. W. 20. 5. 



C. sativa. L. Hemp. This plant, of such immense im- 

 portance for the fibres of its stem, was introduced from Europe, 

 and is partially naturalized. It is of two sorts, one of which is 

 sterile, and dies after fertilizing the flowers of the other kind, 



