BROOM. 399 



3. Shadeb carers, springing up in more or less closed woods. 



4. Weeds of icet or turfy soils. 



5. Lianes. 



6. Parasitic phanerogams. 



7. Weeds acting as hosts to injurious fungi. 



In each group, first the woody species and then herbaceous 

 ones will be considered. 



1. Lightdemanding iveeds. 



These weeds injure forest plants by overtopping them and 

 excluding light and other atmospheric influences, or by 

 occupying the soil with their roots, or in both ways. They 

 may also produce a humus which is unfavourable to forest 

 growth. 



a. Broom (Cytisus scoparius, Link.). 



This evergreen shrub attains six feet and more in height, 

 and prefers deep sandy or loamy soil ; it springs up on clear- 

 ings in mild localities, and is found throughout Europe. The 

 seed may remain dormant in the soil for many years. It may 

 be submerged in water for several decades without losing its 

 germinative power. Burning undergrowtn often results in 

 the germination of dormant broom seed, and in the Ardennes, 

 where basic slag is put on to heather soil, a dense crop of 

 broom often results. 



Broom, when not growing too densely, may be useful to 

 young broadleaved plants, such as oak-saplings and stool- 

 shoots, by affording them shelter against frost, but a dense 

 growth of broom is very destructive to one- and two-year-old 

 pine and larch sowings. 



Protective Measures. 



It is best to uproot the young broom at its first appearance, 

 or it may be cut off at mid-stem, when the stems dry up and 

 do not shoot out again. This plant, as well as all other weeds, 

 should be removed before the seeds are ripe, in this case in 

 July. Its removal may repay the cost, as it is used for litter, 

 fuel, and for making brooms, hedges or thatch. It may be 

 browsed down by sheep. In Italy, between the Alban and 



