A new species of HedysarumL. sect. Subacaulia (Boiss.) B-Fedtsch for the Western Mediterranean zone (Southern Spain)

This paper provides the first description of a Hedysarum species (Hedysarum costaetalentii sp. nov.) of the section Subacaulia (Boiss.) B. Fedtsch dis covered in the Western Mediterranean mountains. This section is considered endemic to the northeastern Mediterranean zone. The discovery of this new s pecies significantly enlarges its area of distribution. H. costaetalentii s p. nov, is a rare plant endemic in the upper part (1900-2100 m) of the Sier ra de la Grillimona (Granada, Spain). It grows among the cushion-shaped scr ubs (dominated by Vella spinosa Boiss.) and dwarf grasses, such as Festuca hystrix Boiss. and F. hackelii K. Richt. H. costa-etalentii is closely rela ted to H. erythroleucon Boiss. The first species is endemic to S. Spain, th e second, to S, and SE. Anatolia. This is a southeastern vicariance recalli ng other pairs of taxa such as Viola delphinanta-V. cazorlensis, Crataegus orientalis-C. presliana, Lonicera nummulariifolia-L. arborea, etc., and sug gesting the ancient origin of this new species.