Chromosome numbers of Norfolk Island endemic plants

Abstract

Documented chromosome numbers are reported for the first time for 11 (encompassing 11 genera and families) of the 49 endemic vascular plants from Norfolk Island. Confirmatory counts are provided for the endemic Achyranthes arborescens and Rhopalostylis baueri var. baueri. At least 11 of the taxa counted are probable polyploids, supporting the common cytological feature of oceanic island floras. In addition to these new counts, we also infer a base number of x = 5 for the recently reinstated monogeneric Pennantiaceae and query the generic placement of the two arborescent species of Achyranthes, A. arborescens and A. margaretarum.