THE WILLOW FAMILY 



SALICACE^ Lindley 



j]WO genera only form this family, including probably 250 species of 

 trees or shrubs of temperate and cold regions, principally of the 

 northern hemisphere, reaching into the arctic regions and to very 

 high altitudes. 



Economically the family produces little of importance; the weak soft wood is 

 a favorite source of fine charcoal. The twigs of some of the tougher willows are 

 largely used for baskets and wickerware; the bark of most of them contains a 

 bitter principle, and is sometimes used medicinally; the astringent bark of some 

 is used to a small extent in tanning. The willows are sparingly planted for shade, 

 but more often along water courses for the protection of their banks. The poplars 

 are much planted for shade trees, mainly on account of their rapid growth, and the 

 wood of several species is largely used in the manufacture of paper pulp. 



The SdicacecR have deciduous, alternate, simple leaves with or without stipules. 

 The flowers are dioecious, in bracted catkins, each flower being sohtary in the axil 

 of a bract; the perianth is represented by a cup-shaped disk or a gland. The 

 staminate flowers consist of i or more stamens, their filaments free or united; 

 anthers 2-celled, the sacs opening lengthwise. The pistillate flowers consist of a 

 one-celled ovary subtended by a small disk and composed of 2 or rarely 4 united 

 carpels; stigmas 2 to 4, more or less united, rarely raised on a short style; the 

 ovules are numerous. The fruit is a dehiscent capsule enclosing numerous seeds, 

 each seed being provided with a dense tuft of hairs at the apex; these are long, 

 silky, and usually white. 



The genera are: 



Bracts of thefflowers more or less cut and fringed; disk cup-shaped; winter buds 



with several scales 1. Populus. 



Bracts of the flowers entire; disk of i or 2 glands; winter buds with but i scale 2. Salix. 



I. THE POPLARS 



GENUS POPULUS [TOURNEFORT] LINNAEUS 



'jOPULUS, the ancient name of the European poplars, was accepted by 

 Linnaeus as the name of the genus which they constitute. Some 27 

 species of these trees exist, inhabiting the north temperate and subarctic 

 zones. One species occurs only in mountainous regions of southern 

 Lower California, and this is the only American member of the genus known, 



i6s 



