122 



BRITISH FLOWERING PLANTS 



that the whole atmosphere round a flowering Lime is 

 filled by the " murmurs of innumerable bees," the 

 species of insects visiting it are few, and Knuth only 

 records twenty. The peduncles are bordered or winged 

 half-way up by a long, narrow, leaf-like, persistent bract 

 (Fig. 66). When the fruits drop this catches the wind 

 and thus the seeds are dispersed. The flowers are incon- 

 spicuous. The strong scent is quite sufficient to attract 

 insects, and bright colours are therefore unnecessary. A 

 remarkable point about the scent of the Lime is that it 

 is said to be strongest about thirty yards from the tree, 

 as if the strength was brought out by some action of 

 the air as it gradually diff'uses. A similar observation 

 has been made in the case of the Vine.^ 



The expanding leaf-buds assume a drooping position, 

 so that the leaves look as if they were being poured out. 

 The advantage thus gained is that 

 radiation of heat is much less than 

 it would be if the leaves were to 

 assume at once their permanent posi- 

 tion. Darwin has shown that this 

 position really does tend to check the 

 eff"ect of radiation. His experiments, 

 he says, " show that leaves com- 

 pelled to remain horizontal at night 

 suff'ered much more injury from frost 

 than those which were allowed to 

 assume their normal vertical position." 

 The winter buds are described in 

 my Buds and Stipules. The foliage 

 leaves are stalked, broadly heart- 

 shaped or nearly orbicular, often 

 oblique, glabrous above, and more or 

 less downy underneath, especially in 

 the angles of the principal veins. The 

 stipules are large and beautiful — a rich 

 crimson or even a bright ruby. On the under side of 

 the leaves at the base where the nerves diverge are more 



' step, Wayside and Woodland Trees. 



Pig. 66.— Fruits and 

 bract of Lime. 



