The mycelium of Botrytis cinerea , which is around 12µm wide, is cylindrical and banded, light brown to olive in color.

When it becomes fruitful, the mycelium forms long conidiophores (figures 1 and 2) at first simple, then branching out by a series of branches arranged perpendicularly, at the end of which are formed conidia inserted in clusters (figure 3). and carried by sterigmata (figure 5).

The conidia ensuring the asexual reproduction of this fungus are unicellular, ovoid, hyaline to slightly brownish (figure 2). They measure 10-12 x 8-10 µm, dimensions that may vary depending on the substrate on which this fungus grows.

Let us add that the conidiophores, surmounted by numerous conidia often grouped together in the form of more or less numerous and extensive tufts, are at the origin of gray mold (figures 6 and 7).

The sclerotia are the main form of conservation Botrytis cinerea . They are small, rounded to ovoid, flattened and measure 2 to 5mm in length. They are first white then gradually brown (figure 8). Fine and regular punctures are observable on their surface.

B. cinerea also forms apothecia brownish, pedicellate , ensuring its sexual reproduction (teleomorph: Botryotinia fuckeliana ). They bear cylindrical asci mixed with filiform paraphyses. The ascospores, 8 in number, are oblong to elliptical and measure 6-9 x 5-6 µm.