black knot

noun Plant Pathology.

a disease of plants, especially of plums and cherries, characterized by black knotlike overgrowths on the branches, twigs, etc., caused by a fungus, Dibotryon morbosa.

Origin of black knot

An Americanism dating back to 1835–45

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for black knot

Historical Examples of black knot

Happily, black-knot may be controlled by cutting out the diseased wood.
The Cherries of New York
U. P. Hedrick
The branches are very liable to disfigurement by the black-knot and the foliage by the tent-caterpillar.
Handbook of the Trees of New England
Lorin Low Dame
The fungus is also related to the black-knot fungus on the plum, but its life-history is not yet known.
Northern Nut Growers Association, Report of the Proceedings at the Fourth Annual Meeting
Various

British Dictionary definitions for black knot

black knot

noun

a fungal disease of plums and cherries caused by Dibotryon morbosum, characterized by rough black knotlike swellings on the twigs and branches

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012