Trichophyton gourvillii. Laboratory petri dish culture of the fungus Trichophyton gourvilli. Here the petri-dish is illuminated from behind. This highlights the growth radiating from the centre and causes the orange tinge at the edges of the culture. The main body of the fungus, known as the mycelium, is dark red. The colour is caused by pigment produced by the fungus. Trichophyton gourvilllii is a rare fungus, known to cause scalp infections in west Africa.