128 Bulletin 145 



FRAGRANT SUMACH. Rhtis Canadensis Marsh. (R aromatica 



Ait.) 



I 

 This is a low straggHng shrub, usually two to four feet | 



high, which occurs only occasionally on rocky banks in western 



Vermont. It is of considerable value in ornamental planting | 



in rocky soil, but otherwise is of less economic interest than the I 



other sumachs. Its popular name was suggested by the fact 



that the leaves, especially when bruised, are slightly aromatic. 



I 



POISON IVY. Rhus toxicodendron L. 



The poison ivy, or three-leaved ivy, is sometimes given the 

 confusing name of poison oak. It is common, especially in moist , 

 woodlands and fence rows, and is so dangerous a plant that every j 

 school child should learn to recognize it. This is easily done by 

 noting the characters of leaf and fruit. The leaflets are always j 

 in threes, with the end leaflet slightly stalked, as sho-wn in the 

 figure. In size and toothing they have a general resemblance , 

 to the common woodbine or five-leaved ivy. The number of 

 leaflets is, however, a sure distinction. The poison ivy is dis- j 

 tinguishable from other three-leaved -woodland plants by its I 

 woody stem and climbing habit. Its dry, greenish-white ber- j 

 ries, the size of small peas, standing in grape-like clusters, are i 

 also a conspicuous character of the older plants. In the mat- ' 

 ter of climbing, however, the plant may vary so widely as to j 

 puzzle botanists. It may stand as a low upright shrub if it has 1 

 nothing to cling to, but usually it develops as a low vine, climbing 

 by rooting stems over old stumps and walls. If well started at 

 the base of a living tree it may, however, climb to indefinite 1 

 height, rooting itself in the bark and injuring the tree as well as , 

 menacing human passers-by. Some persons are severely 

 poisoned by the slightest contact with this shrub, while others , 

 handle it with impunity. Even the latter may well shun it, how- I 

 ever, since if once poisoned they will thereafter remain sus- 

 ceptible. The poison resides in a resinous exudate on the sur- ' 



