Figure 1.

Schematic of expected reproductive interactions (left column) and their short- (centre column) and long-term (right column) outcomes under three scenarios. (a) Two closely related sexual lineages (each species indicated by different-coloured petals). Arrows above the flowers indicate the direction of potential interspecific pollen flow. The smaller size of offspring suggests lower fitness than their parents. (b) Two (obligate) apomictic lineages (designated with a stylized ‘A’ in the ovary), indicating no pollen flow, no hybrid formation and stable co-occurrence. (c) Reproductive interactions of a sexual and an apomictic lineage, showing unidirectional pollen flow from the apomict to the sexual recipient. (Online version in colour.)