Abstract
Somatic chromosome numbers for New Zealand provenances of Phragmites australis are reported. A wide range of cytological variation was encountered—one plant was tetraploid (2n = 4x 2 = 48), two were octoploid (2n = 8x 2 = 96), and two were mixoploid (2n = 48, 53, 54; and 2n = 96, c. 264). One Australian provenance was octoploid. Possible regions of origin for the New Zealand populations are suggested, and multiple introductions postulated, although it is conceivable that some octoploids could be indigenous in a cytodeme shared with Australia.