What is "heterothallic"

a. (context botany of some algae and fungi English) Producing male and female reproductive structures in different plants.

Heterothallic species have sexes that reside in different individuals. The term is applied particularly to distinguish heterothallic fungi, which require two compatible partners to produce sexual spores, from homothallic ones, which are capable of sexual reproduction from a single organism.

In heterothallic fungi, two different individuals contribute nuclei to form a zygote. Examples of heterothallism are included for Saccharomyces cerevisiae, Aspergillus fumigatus, Aspergillus flavus, Penicillium marneffei and Neurospora crassa. The heterothallic life cycle of N. crassa is given in some detail, since similar life cycles are present in other heterothallic fungi.