Stackhousia tryonii Bailey: a Nickel-Accumulating Serpentine-Endemic Species of Central Queensland.

Abstract

Stackhousia tryonii Bailey, which appears to be endemic to the serpentinite soils of the Port Curtis district, central Queensland, is a hyper-accumulator of nickel. Concentrations of this element reach 1-20% of the dry weight of the leaves and 0.1-1% in other parts of the plant. This is the first discovery of such behaviour in a plant from eastern Australia. S. tryonii is easily distinguishable from the Queensland occurrences of a related species, S. monogyna Labill., by its smaller inflorescences and muchbranched, tufted, slender stems and distinctive sparsely tuberculate seed coat. S. monogyna shows no abnormal nickel accumulation. Detailed diagnostic comparative descriptions of S. tryonii and S. monogyna are provided, and notes are given on the ecology and distribution of the two species.