Martin Grings

A New Species of Pavonia (Malvaceae) from Southern Brazil

Abstract Pavonia secreta (Malvaceae) is a new species from Rio Grande do Sul, Brazil. This new species belongs to subgenus Pavonia and is related to P. xanthogloea. Pavonia secreta can be distinguished by the absence of a tuft of long and simple trichomes at the apex of the petiole and on the abaxial side of the leaf, and by paler foliage; it presents dark pink flowers, with larger petals and stem tube; has larger mericarps, which are tuberculate-rugose with 2–3 tubercules on each side. Pavonia secreta is an endemic species restricted to Pedra do Segredo, Morro do Leão and a neighbouring hill, localities that belong to Caçapava do Sul municipality, in southern Brazil. We present a morphological description, illustrations, and ecological data, as well as a key including a morphologically similar species.

Taxonomic and ecological aspects of Myrceugenia mesomischa (Myrtaceae), an endemic tree from southern Brazil

Myrceugenia mesomischa (Burret) D. Legrand & Kausel (Myrtaceae), a tree species poorly cited in floristic and phytosociological surveys in its area of known occurrence, was recorded as one of the species with the highest importance value in a fragment of Araucaria forest in Sao Francisco de Paula municipality, Rio Grande do Sul state, Brazil. The species was abundant in the understory strata of the forest, showing the highest frequency and density of the survey. Considering the paucity of data on the species, its degree of rarity and endemism (occurring only in the states of Rio Grande do Sul and Santa Catarina, Brazil), more studies are needed to evaluate the true current state of conservation of populations of this species.