THE BURDOCK. 159 



even more; the lower leaves are very large, frequently 

 more than a foot long, heart-shaped, and of a grey colour 

 on their under surface, from the mass of fine down with 

 which they are covered. The upper leaves are considerably 

 less in size, more ovate in form, and not so densely clothed 

 beneath with the grey down that is so marked a feature 

 in the lower leaves. The involucre is almost spherical in 

 form, and thickly covered with bracts, each terminating 

 in a sharp point that is bent into a hook-like form the 

 peculiarity that enables them to grasp so tenaciously any 

 suitable object that chances to touch them. The florets 

 are all tubular, similar, and of a purple colour. 



Though it is ordinarily held that we have but one 

 species of burdock, it is a plant that varies a good deal 

 in appearance; and some observers have held that these 

 differences are sufficient, not merely to be recognised as 

 varieties, but to justify them in creating four distinct 

 species. It is, however, held by most botanists that the 

 characters on which these specific differences are founded 

 are scarcely sufficiently satisfactory to justify the division. 

 The size of the flower-heads and of the whole plant, the 

 abundance of the white cotton-like substance that is 

 sometimes found on the involucres, or the absence of it, 

 the length of the peduncles, and some few other minor 

 points, are the features that, by their variation in different 

 plants, have led to the attempt to set up forms of fixed 

 and specific value. 



For the ordinary observer, the long-established belief 

 that we have but one species is amply sufficient for practical 

 field-work ; but as these varieties we have referred to are 

 often met with, it may be well briefly to refer to them. 



In that which is by some observers made a species 



