Botrytis cinerea is a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes. In viticulture, it is commonly known as botrytis bunch rot; in horticulture, it is usually called grey mould or gray mold. The fungus gives rise to two different kinds of infections on grapes. The first, grey rot, is the result of consistently wet or humid conditions, and typically results in the loss of the affected bunches. The second, noble rot, occurs when drier conditions follow wetter, and can result in distinctive sweet dessert wines, such as Sauternes or the Aszú of Tokaji.

The species name Botrytis cinerea is derived from the Latin for "grapes like ashes"; although poetic, the "grapes" ("botrytis" from Ancient Greek botrys (βότρυς) meaning "grapes" (Liddell & Scott 1940) plus the Neolatin suffix -itis for disease) refers to the bunching of the fungal spores on their conidiophores, and "ashes" just refers to the greyish colour of the spores en masse. The fungus is usually referred to by its anamorph (asexual form) name, because the sexual phase is rarely observed. The teleomorph (sexual form) is an ascomycete, Botryotinia fuckeliana, also known as Botryotinia cinerea.

European waters (ERMS scope)

Foodplant / pathogen
effuse colony of Botrytis dematiaceous anamorph of Botrytis cinerea infects and damages fruit of Herbaceous Plants

Foodplant / saprobe
effuse colony of Botrytis dematiaceous anamorph of Botrytis cinerea is saprobic on dead stem of Heracleum sphondylium

Foodplant / pathogen
Botrytis dematiaceous anamorph of Botrytis cinerea infects and damages live Humulus lupulus

Foodplant / pathogen
Botrytis dematiaceous anamorph of Botrytis cinerea infects and damages rotten stem of Lactuca sativa

Foodplant / pathogen
Botrytis dematiaceous anamorph of Botrytis cinerea infects and damages live fruit of Lycopersicon esculentum

Foodplant / saprobe
colony of Botrytis dematiaceous anamorph of Botrytis cinerea is saprobic on dead stem of Urtica dioica

Foodplant / pathogen
fluffy colony of Botrytis dematiaceous anamorph of Botrytis cinerea infects and damages live twig (base) of Ficus carica

Foodplant / pathogen
effuse colony of Botrytis dematiaceous anamorph of Botrytis cinerea infects and damages rotting flower of Dendranthema

Foodplant / pathogen
effuse colony of Botrytis dematiaceous anamorph of Botrytis cinerea infects and damages green parts of Hydrangea

Foodplant / pathogen
colony of Botrytis dematiaceous anamorph of Botrytis cinerea infects and damages wilted stem of Paeonia

Foodplant / pathogen
colony of Botrytis dematiaceous anamorph of Botrytis cinerea infects and damages rotting stem of Saintpaulia ionantha

Inhibits or restricts the growth of
colony of Trichoderma inhibits sclerotium of Botrytis cinerea
Remarks: captive: in captivity, culture, or experimentally induced