Variation in Phebalium glandulosum subsp. glandulosum: morphometric and anatomical evidence (Rutaceae)

Abstract

Specimens of Phebalium glandulosum Hook. subsp. glandulosum representing the entire geographic range of the subspecies were examined for morphological and anatomical variation. Phenetic patterns were identified with the pattern analysis package PATN, and three distinct groups were identified. One group consists of plants from inland areas of New South Wales, north-western Victoria, and the Yorke and Eyre Peninsulas of South Australia; a second group consists of plants collected from alongside the Snowy River in eastern Victoria and south-eastern New South Wales; and a third group consists of plants from Queensland and northern New South Wales. The climate analysis program BIOCLIM was used to compare climate variables across the geographic range, and showed clear climatic separation in support of the phenetic analysis. The three groups are formally recognised here as distinct subspecies. Plants from Queensland and the Bourke region of northern New South Wales belong to the typical subspecies; plants from north-western Victoria, central New South Wales, and the Yorke and Eyre Peninsulas of South Australia form a cohesive assemblage and are recognised as a new subspecies P. glandulosum subsp. macrocalyx; and plants from the Snowy River in far eastern Victoria and the Southern Tablelands of New South Wales form a distinct and isolated group recognised as a new subspecies P. glandulosum subsp. riparium. These new subspecies are formally described, and an identification key and summaries distinguishing all six subspecies of P. glandulosum are presented.