XL.— THE GOAT WILLOW. 
Salix caprea Linne. 
T HERE is probably no genus of plants which more deserves the epithet 
“ troublesome,” applied to it by Sir Joseph Hooker, than does the genus 
Salix. This is not because there is any difficulty in recognising a plant as belonging 
to the genus. Willows range in size from small herbaceous plants to large trees. 
Their simple stipulate leaves vary much in outline and texture. They are all, 
however, dioecious : their staminate and carpellate flowers are both in catkins : the 
catkin-scales are not notched : there is no trace of a perianth, but there are honey- 
secreting glands in both male and female flowers ; and the stamens are from two to 
five in number in the axil of each scale on the male catkin. The carpels are 
uniform in character, there being invariably two, united in a one-chambered ovary 
with two parietal placentas bearing numerous ovules. The ovary becomes a dry 
capsular fruit dehiscing into two valves and exposing a multitude of seeds each 
enveloped by a tuft of cottony hairs springing from its base. 
The difficulty is in limiting and determining the species. Being dioecious, each 
species must have two forms, staminate and carpellate, and these often differ 
considerably in other characters than their catkins. There is unquestionably a very 
large amount of variation within the limits of each species, partly as the result of 
varying conditions of soil, exposure, temperature, etc. Hybridism occurs to a very 
large extent, even among Willows living under purely natural or wild conditions. In 
our withy-eyots or osier-beds we have also forms of foreign origin as well as our 
numerous native species. As some suggestion of the confusion thus produced in 
the minds of botanists, we may point out that Loudon described over two hundred 
forms as growing in the Saliceta which were not uncommon in his time ; Sir 
William Hooker enumerated seventy species as British and Sir J. E. Smith, who 
denied hybridism, sixty-four species, besides three named varieties ; Babington, 
Koch, and Lindley reduced the number of species to thirty, though the first-named 
authority also enumerated some fifty varieties ; Andersson, who is followed by 
Sir Joseph Hooker and by the Rev. E. F. Linton, the latest monographer of our 
British forms, makes only eighteen British species ; and Dr. Buchanan White only 
seventeen, nearly all the “ varieties ” of earlier writers being now recognised as 
hybrids of which the parentage has, in many cases, been determined. 
The difficulty of the study of Willows arises partly from the necessity of 
collecting flowers and leaves at different seasons and partly from the varied changes 
which the trees undergo in pubescence, in shape of catkins, in the colour of the tips 
of the bracts, and in the length of the pedicel of the ovary, during the course of 
development. 
Willows have apparently a geological antiquity nearly, if not quite, as great as 
that of Poplars, dating at least from Cretaceous times ; and this, coupled with a 
