POLYGONUM ARIFOLIUM. HALBERD-LEAVED TEAR-THUMB. I 55 



any " ; for the husbandman, for vei-y good reasons, often calls 

 " a weed " what others delight in as a beautiful flower. It is all 

 the more singular to find, on the other hand, that Dr. W. C. P. 

 Barton, who is apt to be more tart than Dr. Darlington, has a 

 good word for our plant. This author, in his " Flora of North 

 America," after explaining that the plant is called " Tear- 

 Thumb," because its sharp prickles are apt to tear the fingers 

 of those who handle it, adds that " in favorable situations it is 

 not destitute of beauty." This is, indeed, but negative praise, 

 but it is better than downright condemnation. The specimen 

 which Dr. Barton selected for the illustration in his work is of 

 the paler, denser-headed kind. We have purposely chosen a 

 darker-colored and more slender-flowered kind, so as to show 

 the beauty which the plant often possesses, and at the same 

 time to enable the reader, by comparison with Dr. Barton's 

 plate, to get some idea of the great range of its variation. 



Polygointin arifoUum not only grows wild in meadows, as 

 noted by Dr. Darlington, but it is even more at home in grounds 

 so wet as to be almost ponds at certain seasons of the year. The 

 seeds, in fact, will germinate in water, under favorable circum- 

 stances. When clambering over an isolated bush, our plant 

 forms a truly beautiful object ; and in some swampy spot in a 

 garden, or with the aid of an artificial arrangement suited to its 

 habits, it might, with a little care, be made a very attractive 

 feature, — provided that its " thumb-tearing " qualities are no 

 objection. 



The thorny prickles with which the plant is armed have long 

 been an object of study to those who love to fathom the secrets 

 of nature. Dr. Erasmus Darwin, who lived eighty years ago, and 

 was, like the modern Darwin, an evolutionist, wrote a curious book 

 called " Phytologia," in which he advanced the idea that all plants 

 were originally thornless, and that the thorns were only formed 

 as a sort of protection against injury, after insects and other 

 animals had appeared on the earth. Linnaeus also had regarded 

 these appendages as the "armor of plants," but he had not gone 



