Merrill (Philip. J. Sc. 2, 1907, Bot. 284) based Mearnsia on specimens collected from Mount Halcon in the Phillipines and dedicated the genus to Major Mearns who accompanied him on the expedition. Merrill described the flowers of the sole species (M. halconensis) as 4-merous with 8 stamens and 2 carpels and the capsule as dehiscing by ‘a single slit at the apex only and inside the persistent calyx tube’.