Dioecism in New Zealand escalloniaceae

Abstract

It has been generally accepted that flowers of the three New Zealand genera of the Escalloniaceae (Carpodetus, Quintinia and Ixerba) are hermaphrodite (Allan, 1961). Evidence is presented in this paper that in Carpodetus serratus female flowers and hermaphrodite flowers (i.e. gynodioecism) occur on separate plants in approximately equal numbers in all populations studied. The majority of hermaphrodite plants bear no fruit, but in about 12% sparse fruiting occurs, which shows the gynoecium is potentially fertile. In Quintinia acutifolia female flowers with non-functional anthers are borne on about 40% of the plants; the rest bear male flowers in which the stigmatic lobes never develop fully and fruit is never found. Populations of Q. serrata and Q. elliptica have not been investigated, but male and female flowers have been observed in herbarium material of these species. The fifth New Zealand species, Ixerba brexioides is hermaphrodite.