gallnutter

Gallnutter is a colloquial term, primarily used in some parts of the United Kingdom, referring to a type of small, often unusually shaped, nut-like gall that forms on certain trees and plants. These galls are abnormal growths caused by the larvae of small insects, typically certain species of wasps or midges, that lay their eggs in the plant tissue. The plant's reaction to the insect's feeding or the presence of its larvae leads to the formation of these localized swellings.

The term "gallnutter" is not a scientific classification but rather a descriptive, informal name. The appearance of gallnutters can vary greatly depending on the specific insect species and the host plant. They can range in size from a few millimeters to a couple of centimeters and may be smooth, spiky, or have other textural variations. Common host plants include oak trees, but other species like willows and roses can also be affected. The exact biological mechanisms behind gall formation are complex, involving chemical signals exchanged between the insect and the plant. While gallnutters are a natural phenomenon, they are sometimes collected for their interesting shapes and textures, though their practical uses are limited.