Abstract

Previously unpublished chromosome numbers of n = 10 are reported for species of Lasiopetaleae genera Lasiopetalum, Seringia and Guichenotia. Additional new chromosome numbers of n = 10 for species of Keraudrenia and Thomasia match published records for these genera and other Lasiopetaleae Lysiosepalum and Hannafordia. There is one count of n = 20 for Thomasia angustifolia which is interpreted as a polyploid number. New counts of n = 10 are recorded for species of Rulingia and Commersonia, traditionally included in Byttnerieae, but with affinities to Lasiopetaleae. Comparison of Lasiopetaleae chromosome numbers with other members of the subfamily Byttnerioideae and the closely related Grewioideae (Malvaceae s.l.) shows no clear evidence for a trend towards either reduction or increase in chromosome number within the groups.