witches'-broom

American  

[wich-iz-broom, -broom] / ˈwɪtʃ ɪzˌbrum, -ˌbrʊm /

noun

Plant Pathology.

1. an abnormal, brushlike growth of small thin branches on woody plants, caused especially by fungi, viruses, and mistletoes.

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witches'-broom British  

/ ˈwɪtʃˌbruːm /

noun

1. a dense abnormal growth of shoots on a tree or other woody plant, usually caused by parasitic fungi of the genus Taphrina

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Etymology

Origin of witches'-broom

First recorded in 1865–70

Example Sentences

They are the very opposite, and they don't want to be pruned, and if you go pruning them, they are likely to have the witches'-broom.

From Northern Nut Growers Association Report of the Proceedings at the 41st Annual Meeting Pleasant Valley, New York, August 28, 29 and 30, 1950 by Northern Nut Growers Association

The names "brooming" and "witches'-broom" have already been applied to diseases caused by fungi.

From Northern Nut Growers Association Report of the Proceedings at the Forty-Second Annual Meeting Urbana, Illinois, August 28, 29 and 30, 1951 by Northern Nut Growers Association

The bunchy top or witches'-broom caused by a virus, that is serious on the Japanese walnut, Juglans Sieboldiana, does not appear to be so virulent on butternut.

From Northern Nut Growers Association Report of the Proceedings at the 41st Annual Meeting Pleasant Valley, New York, August 28, 29 and 30, 1950 by Northern Nut Growers Association

Some of the heartnut trees have developed a disease called witches'-broom or bunch disease.

From Northern Nut Growers Association Report of the Proceedings at the 41st Annual Meeting Pleasant Valley, New York, August 28, 29 and 30, 1950 by Northern Nut Growers Association

When Mr. Burgart up in Michigan finds out that the limiting factor practically cleans him out, there is this question of bunch disease with witches'-broom resulting from ground deficiency.

From Northern Nut Growers Association Report of the Proceedings at the 41st Annual Meeting Pleasant Valley, New York, August 28, 29 and 30, 1950 by Northern Nut Growers Association