A New Species of Matelea (Apocynaceae, Asclepiadoideae) from the Peninsula de Nicoya, Guanacaste, Costa Rica

We describe and illustrate a new species of Matelea Aubl. from Peninsula de Nicoya, Costa Rica. Matelea nicoyana J. E. Jimenez, M. Mendez & J. A. Obregon is morphologically similar to M. pseudobarbata (Pittier) Woodson but is distinguished by its stems with dispersed, pilose trichomes, leaf blades without pilose trichomes and with 12 to 15 colleters, calyx lobes deltate, inflexed, and corolla with reflexed and contorted lobes covered by white-translucent, flexuous trichomes adaxially. Data on its distribution and habitat, phenology, conservation status, and morphologically related species are given and photographs are presented. A dichotomous key is presented for species from Costa Rica sharing similar indument. The species proposed here increases the number of Matelea species in Costa Rica to 17, nine of which are endemic.

Automated summary

We describe and illustrate a new species of Matelea Aubl. from Peninsula de Nicoya, Costa Rica. The new species, Matelea nicoyana, is similar in morphology to Matelea pseudobarbata but can be distinguished by its stem characteristics, leaf blade features, calyx lobe shape, and corolla trichome structure. Information on distribution, habitat, phenology, and conservation status, as well as related species, are provided.