Disintegration of Polyalthia debilis (Annonaceae): P. Cambodica comb. nov., P. canaensis comb. et stat. nov., and P. suthepensis nom. nov. For Unona dubia

Abstract

Polyalthia debilis (Annonaceae), a widespread species in Cambodia, Thailand, and Vietnam, is recircumscribed by morphological reappraisal. Three heterotypic synonyms of Polyalthia debilis, viz. Popowia cambodica, Popowia cambodica var. canaensis, and Unona dubia differ from Polyalthia debilis and from each other by different combinations of the following traits: plant height, leaf blade size, petiole length, flowering pedicel length, inner and outer petal size, number of carpels per flower, number of ovules per ovary, and stipe length. Consequently, each heterotypic synonym deserves recognition as a separate species. Polyalthia cambodica comb. nov. and Polyalthia canaensis comb. et stat. nov. are accordingly made; and Polyalthia suthepensis, a replacement name for Unona dubia, is proposed because the name Polyalthia dubia pre-exists. A key to Polyalthia debilis, Polyalthia cambodica, Polyalthia canaensis, and Polyalthia suthepensis is provided.