Witch's broom

Witches' broom or thunder bushes are usually called in the crowns of fir and birch and spherical bushy adhesions.

Description

While occurring in fir witches 'broom caused by a rust fungus with intermediate hosts of the family Caryophyllaceae (fir cancer), the Birch witches' broom caused by a simply constructed nature of ascomycetes ( Ascomycota ), namely Taphrina betulina. This forms on the surface of the birch branches from tiny tubes. This causes permanent growth disorders by repeatedly driving the birch to bud and formation of so-called dormant buds. This has the consequence that it comes to the attack points to a branch of addiction: the formation of numerous thin and short branches that are called witches' broom. These structures have a similarity with broom older style of a staff, and birch branches. The mycelium of the fungus survives in the bark of the branches. In the crown, especially birch, may arise which sometimes become very large very many witches broom. Consequently, they also affect the growth of the tree negatively.

Even witches' broom in other hardwoods are often caused by Taphrina species.

At larches an infestation could be detected by rickettsia - like organisms as the cause of witches broom -like habit. Also like ash and black locust plant pathogenic viruses can be the cause of some tree species. Witches' broom of spruce and pine are usually not caused parasitic, but are caused by inherited mutations buds, which are used in breeding to meet as tall conifers, ornamental forms.

Distinction

In some places, even from a distance the similar appearing mistletoes are called witches' broom.

245965
de