THE AMERICAN BOTANIST. 35 



under the tree will be found thickly strewn with the broken 

 twigs. 



One of our most common willows is the one known as 

 Bebb's willow, (S. Bcbbiano; S. rosfrata). It is a shrub or 

 small tree and unlike most of its relatives it is often found 

 growing in dry situations, sometimes on rocks where the soil 

 is poor and scanty. It is easily recognized and when once 

 known need not afterward be confused with other willows. 



The heart-leaved willow (S. cordata) is a shrub sometimes 

 reaching a height of twelve feet and can be recognized by its 

 large serrulate and persistent stipules. This species is said 

 to occasionally cross with the glaucous willow (S. discolor) 

 the latter a fine, large-leaved species having the under side of 

 its leaves glaucous and nearly white, and making it easy to rec- 

 ognize at a distance if the wind be blowing enough to turn the 

 leaves. Another species not easily mistaken is the prairie 

 willow (S. hiniiilis), which has pubescent twigs and long 

 leaves, with slightly inrolled margins, covered beneath with 

 a dense, grayish down. 



In swamps and bogs one sometimes meets with the small 

 hoary willow, (S. Candida), usually not more than five feet in 

 height. This is a rarity with us, and I know of only one sta- 

 tion where it inhabits a sphagnum bog along with some of our 

 native orchids and other rare plants. 



Perhaps the most common of all the shrubby forms is the 

 silky willow, (S. scricea) which inhabits swamps and the mar- 

 gins of streams almost everywhere from Maine to Michigan. 

 Of tree forms probably the most abundant is the black willow 

 (S. nigra) or its variety falcata. This is a beautiful tree and 

 well worthy of preservation. Its narrow scythe-shaped leaves 

 and its graceful manner of growth make it a conspicuous tree 

 along our river courses. 



Time and space would fail me to speak of all the numerous 

 forms of this interesting group of plants, but its species are of 



