Tree Study 



767 



with finely toothed edges and short petiole; the exact shape of the leaf, 

 of course, depends upon the species, but all of them are much lighter in 

 color below than above. The willows are, as a whole, water lovers and 

 quick growers. 



Although willow wood is soft and 

 exceedingly light, it is very tough when 

 seasoned and is used for many things. 

 The wooden shoes of the European 

 peasant, artificial limbs, willowware, 

 and charcoal of the finest grain used in 

 the manufacture of gunpowder, are all 

 made from the willow wood. The 

 toughness and flexibility of the willow 

 twigs have given rise to many indus- 

 tries; baskets, hampers, carriage bodies 

 and furniture are made of them. To 

 get these twigs the wiUow trees are pol- 

 larded, or cut back every year between 

 the fall of the leaves and the flow of 

 the sap in the spring. This pruning 

 results in many twigs. The use of wil- 

 low twigs in basketry is ancient. The 

 Britons fought the Roman soldiers from 

 behind shields of basket work ; and the 

 wattled huts in which they lived were 

 woven of willow saplings smeared with 

 clay. SalicyHc acid, used widely in 

 medicine, is made from willow bark, 

 which produces also tannin and some 

 unfading dyes. 



There are many insect inhabitants 

 of the willow, but perhaps the most 

 interesting is the little chap which 

 makes a conelike object on the twig of 

 certain species of willow growing along 

 our streams. This cone is naturally 

 considered a fruit by the ignorant, 

 but we know that the willow seeds are 

 grown in catkins instead of cones. 

 This willow cone is made by a small 

 gnat which lays its egg in the tip of 

 the twig; as soon as the little grub 

 hatches, it begins to gnaw the twig, 

 and this irritation for some reason stops 

 the growth. The leaves instead of de- 

 veloping along the stem are dwarfed 

 and overlap each other. Just in the center of the cone at the tip of the twig 

 the little larva lives its whole life surrounded by food and protected from 

 enemies ; it remains in the cone all winter, in the spring changes to a pupa, 

 and after a time comes forth — a very delicate Httle fly. The larva in this 

 gall is very hospitable. It has its own little apartment at the center but does 

 not object to having a tenant in its outer chambers, a fact which is taken 



The pistillate blossoms of the willow. 



Photo by Verne Morton. 



