Formae speciales in the context of "Fusarium wilt"

Fusarium wilt is a common vascular wilt fungal disease, exhibiting symptoms similar to Verticillium wilt. This disease has been investigated extensively since the early years of this century. The pathogen that causes Fusarium wilt is Fusarium oxysporum (F. oxysporum). The species is further divided into formae speciales based on host plant.