Chromosome numbers in Epacridaceae were collated from various authors
and superimposed on to recent cladograms for the family. The results s
trongly indicate that reduction in chromosome number occurs with evolu
tionary advancement. Thus Epacridaceae, in common with 'Ericaceae sens
. strict.' and 'Vacciniaceae sens. strict.', has evolved from a primit
ive karyotype of at least x = 12 and probably x = 13. This conclusion
dispels earlier paleopolyploid models based on a primitive x = 6 in th
e family. Other aspects of cytoevolution, such as chromosome number as
a generic character especially in cytologically advanced genera of th
e Styphelieae, are discussed. (C) 1997 Annals of Botany Company.