400 PROTECTION AGAINST PLANTS. 



Sabine mountains, regular crops of broom are cultivated with 

 rotations of five or six years, and used for fuel. 



5. Furze (Dies). 



There are two species of furze common in Britain, Ulex 

 suropaeus, L., and U. nana, Forst. The latter blossoms in 

 the autumn, when the larger species is in fruit, the former in 

 the spring and early summer. 



In order to clear furze from tracts that are to be planted, it 

 is best to burn it in the summer, and then cut down the 

 burned stems. It grows slowly from the rootstocks, and a 

 new plantation will come away from it. 



There are several species of Genista, termed in England 

 dyer's- weed, needle-furze, etc., which may be treated like 

 broom, but are never so troublesome here as on the Continent. 



c. Wild Briar (Rosa). 



There are several species of wild briar, the commonest being 

 liosa canina, L. They spring up wherever the soil is not too 

 wet, both in plains and hills. Their great power of sending 

 out suckers renders them very injurious to forest growth, and 

 the best way to get rid of them is to dig them up by the 



roots. 



d. Common Ling and Heather. 



Ling (Calluna vulgaiis, Salisb.), Scotch heather (Erica 

 cinerea, L.),and cross-leaved heather (E. Tetralix,Ij.),&B well 

 as other species of Erica, cover large areas, the first chiefly in 

 Central and Northern Europe, the second in Western Europe, 

 from the south of Spain to Norway, and the last to the west 

 in Southern Europe, but in the north extending eastwards as 

 far as Sweden and Livonia. They grow in very variable soils, 

 but prefer sandy tracts, especially when poor and dry. A 

 luxuriant growth of heather is a sure sign of a poor, shallow, 

 sandy soil, or of one that may have become impoverished by 

 bad management. Heather is injurious not only by filling 

 the ground with its roots, and excluding atmospheric influ- 

 ences, but also by producing as it decays an unfavourable 

 humus, on which only pines, birch and aspen thrive. It is 

 highly inflammable in the spring, and when burning in dry 

 windy weather may cause extensive conflagrations in coniferous 



