HEATHER 17 



The prevalence of Heather over wide areas is an indication 

 of its suitability to the peculiar conditions of life to which it is 

 exposed. These will be more fully discussed in another section of 

 this work, but it may be mentioned that the whole build of this 

 low shrub, with very small leaves, the lower surface of which is 

 reduced, is such as to lessen the loss of water in transpiration. This 

 is necessary, for, while evaporation is favoured by the wind, the 

 peaty soil in which the plant grows makes the absorption of 

 water by the roots difficult. 



Two common species of Heath will usually be found growing 

 in the same districts as the Heather, and may be mentioned. They 

 are the Fine-leaved Heath (Erica cinerea, L.) and the cross-leaved 

 Heath (Erica tetralix, L.). 



ROSE BAY WILLOW-HERB (Epilobium angusti folium, L.) 



There are a number of British species of Willow-Herb, but the 

 largest and showiest is the Rose Bay or French Willow. This 

 occurs wild in many districts throughout the country, and can 

 also be readily obtained in cultivation. The plant is a perennial 

 herb, all the parts above ground dying down in the autumn. New 

 aerial shoots are sent up from the underground stem in the spring. 

 These attain a height of three or four feet, and, since numerous 

 shoots often grow together, the plant forms a conspicuous mass of 

 foliage, which becomes a more prominent object in the landscape 

 when the rose-coloured flowers are open. 



The aerial shoots consist of a cylindrical green or reddish stem, 

 bearing long, narrow, oval, pointed leaves which have practically no 

 stalks. The leaves stand either singly at the nodes or form whorls 

 of three. The blade, which is deep green above, paler beneath, 

 has a well-marked midrib, and this, with the larger branches of 

 the network of veins, projects on the lower surface. 



The flowers are borne in inflorescences, which terminate the 

 main shoot and lateral branches. In the region bearing the 

 flowers the leaves are reduced to small elongated bracts, in the 

 axil of each of which a single flower stands. The lowest flowers 

 open first, and there is a long succession of buds, so that old in- 

 florescences bear almost mature fruits below, while there are still 

 unopened buds at the summit. 



VOL. IV. 2 



