180 RHAMNACEAE 



It is the commonest and most abundant of the buckthorns in 

 Illinois and ranges from the eastern to the western boundary 

 and from the northern boundary southward at least as far as 

 St. Clair and Effingham counties. 



RHAMNUS ALNIFOLIA UHeritier 

 Alder-Leaved Buckthorn 



The Alder-Leaved Buckthorn, fig. 44, is a low shrub with 

 reddish-brown, smooth bark, which seldom reaches a height 

 of more than 3 feet. The branchlets are at first more or less 

 pubescent but become smooth and gray by the end of the sea- 

 son. The leaves are oval or slightly obovate, 1^ to 5 inches 

 long by }i to 2l/^ inches wide, acute or acuminate at the apex, 

 more or less narrowed at the base, and crenulate-serrate on 

 the margins. The surface is smooth above, except the midrib 

 and the upper surface of the petiole, and smooth beneath at 

 maturity, although the main nerves may remain more or less 

 pubescent. The lower leaves are often smaller than the outer 

 leaves and more rounded at the tip. 



The small, greenish-yellow flowers, which appear in late May 

 and early June, stand alone or in clusters of 2 to 3 in the axils 

 of lower leaves on short, glabrate pedicels. The black, bloom- 

 covered fruit, which matures in August, is obovoid, about one- 

 third inch long, and contains 1 to 3 more or less tuberculate 

 nutlets bearing 2 grooves on the back. 



Distribution. — The Alder-Leaved Buckthorn prefers bogs 

 and swamps. It ranges from Newfoundland to British Colum- 

 bia and south to New Jersey and Illinois, inland, and northern 

 California on the western coast. In Illinois, it is at present 

 limited to the northeastern corner of the state, where it is 

 common, although formerly, like a number of other bog plants, 

 it grew in Peoria and Tazewell counties. 



RHAMNUS CAROLINIANA Walter 



Carolina Buckthorn 



The Carolina Buckthorn, fig. 44, is a tall shrub, or occa- 

 sionally a small tree, the branchlets of which are at first 

 puberulent and green but later glabrate and gray. The leaves, 

 often 6 inches long by 2 inches wide, are broadest beyond the 



