ascolocular (adjective) – asci arranged within pre-formed locules; referring to one of two general types of ascocarp development: In the ascolocular ontogeny ascocarps develop from an ascostroma formed by somatic, undifferentiated hyphae. The ascostromatic hyphae first differentiate into the primordium by the formation of locules. As a result of fertilization, generative, ascogeneous hyphae then grow into the pre-formed locules. The ascolocular development thus begins with the aggregation of somatic hyphae into an ascostroma, followed by the differentiation of the ascostroma into locules, which are ultimately invaded by generative hyphae that finally form asci. The result is the formation of a pseudothecium, i. e., an ascocarp that may frequently look apothecioid, perithecioid or cleistotheciod but derived from a very different ontogeny. This ontogeny can only be observed if all stages of ascocarp development are studied consecutively. Primordia need to be compared with premature, immature and mature ascocarps because mature ascocarps of lichenized fungi frequently persist for several generations and new asci can be formed within existing ascocarps with every new season.