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 contrib...
The condition of being self-sterile, requiring a partner for sexual reproduction. 
<plant biology> Situation in some fungi and algae in which there are two mating types and the individual thallus is self sterile even if hermaphrodite. ... (18 Nov 1997) ... 
The condition in which fungi produce compatible male and female gametes on physiologically distinct mycelia.Situation in some fungi and algae in which there are two mating types and the individual thallus is self-sterile even if hermaphrodite.
Type: Term Pronunciation: het′ĕr-ō-thal′ik Definitions: 1. In fungi, denoting a kind of sexual reproduction in which a sexual spore is produced only by fusion with a nucleus of another mating type.
heterothallic, heterothallism Referring to algae and fungi, describing the condition in which there are two mating types that act as male and female, as opposed to one self-fertile individual.