Morphological and molecular evidence refute a broad circumscription for Pultenaea glabra (Fabaceae: Mirbelieae), with implications for taxonomy, biogeography, and conservation

Abstract

Morphological and single-nucleotide polymorphism data support splitting Pultenaea glabra Benth. into eight species, including one in Victoria, and seven in eastern and northern New South Wales. Six species are newly described, five of which are, like P. glabra, narrow-range endemics within the Greater Blue Mountains World Heritage Area and adjacent sandstone landforms of the Great Dividing Range. The recognition of six new species from what was broadly P. glabra has implications for conservation management, including for P. glabra itself, which has a smaller distribution and more precise habitat requirements than previously thought. One of the new species, P. percussa, is known by a single 1971 gathering only. The occurrence of several narrow-range Blue Mountains endemic Pultenaea species may be explained by the combination of edaphic diversity and topographic complexity, which could act in concert to promote divergences among small, allopatric populations. Hybrids between P. glabra and P. flexilis Sm. are documented for the first time; however, limited evidence for introgression between the two species was observed. The following new taxa are described: Pultenaea aculeata M.A.M.Renner, P.H.Weston & S.Clarke, Pultenaea percussa M.A.M.Renner & P.H.Weston, Pultenaea furcata M.A.M.Renner & R.L.Barrett, Pultenaea mutabilis M.A.M.Renner & P.H.Weston, Pultenaea mutabilis var. angusta M.A.M.Renner, P.H.Weston, & S.Clarke, Pultenaea praecipua M.A.M.Renner & P.H.Weston, Pultenaea praecipua subsp. temperata M.A.M.Renner & R.L.Barrett, and Pultenaea tenebrosa M.A.M.Renner, P.H.Weston & S.Clarke. Lectotypes are designated for Pultenaea villosa var. glabrescens Benth. and Pultenaea weindorferi Reader.