34 SALICACEAE 



SALICACEAE 

 The Willow Family 



This family is made up of trees, shrubs and herbs, which 

 bear simple, alternate leaves and produce pistillate and stami- 

 nate flowers in deciduous catkins, the two kinds of flowers be- 

 ing borne on separate plants. The fruit is a small, lanceolate 

 capsule, which splits lengthwise into 2 recurving valves to liber- 

 ate numerous oblong, tiny seeds, each of which has a small tuft 

 of down at its base. There are no sepals or petals in the flowers. 

 The bark of all members of the family is bitter. 



Of wide distribution and great usefulness, the willow family 

 is represented in Illinois as trees by both willows and poplars; 

 17 species of willow shrubs are native in the state. 



SALIX (Tournefort) Linnaeus 

 Willows Osiers 



The willows may be trees, shrubs or herbs, the shrubby forms 

 having clustered stems, round, slender branchlets, variously 

 shaped leaves, and catkins that appear before, with or after the 

 leaves. 



Salix is a very large and complex genus, of wide distribution 

 in the world. In Illinois, only trees and shrubs are present, and 

 these are useful for many purposes, including basket withes, 

 charcoal, ornamental plantings and hedges. The members of 

 the genus are very difficult to identify with certainty by vegeta- 

 tive characters alone. For accurate identification, it is desir- 

 able to have both flowers and fruit. 



Key to the Willow Species 



Because of the confusion that might arise in mistaking for shrub 

 species the young specimens of native or naturalized tree-size 

 species, the key given below includes both shrubby and tree species. 



I. Leaves green on both sides. 



A. Margins remotely denticulate, teeth spinulose. 



B. Blades long and very narrow, acute at both base and 



apex (2-4^ by l4-]/i inches) 



S. longifolla, p. 40 



B. Blades oblong (2-4 by l4-H inches) 



S. longifolia var. Wheeleri, p. 42 



A, Margins closely serrate. 



C. Blades linear-lanceolate (tree) S. nigra 



1 



