Breeding systems in New Zealand grasses

Abstract

The South American species of Cortaderia naturalised in New Zealand are C. selloana and another species, probably C. atacamensis. The genus has long been considered dioecious, but C. selloana is gynodioecious as are the three species indi~enous to New Zealand. In the populations of C. sel/oana examined in New Zealand the ratio of hermaphrodites to females is 1:1. Cortaderia atacamensis occurs here as female plants only and reproduces freely by seed produced in an autonomous apomictic process. Gynodioecism is reported in the South American species C. pilosa and C. araucana.