Expanding the Distribution of Prosthechea jauana (Orchidaceae) in the Pantepui and Highlighting the Urgent Need for Conservation Strategies in the Region in Face of Climate Change.

Prosthechea jauana has been recognized as an orchid species endemic to the Venezuelan tepui. The first record of P. jauana in Brazil is presented here, also from a tepui in the Southern phytogeographical district of Pantepui in the Serra do Aracá, at the northern border of the Amazonas state. A detailed morphological description and images of the specimen are presented, as well as an updated distribution map, preliminary conservation status assessment, and taxonomic notes about the species. In addition, we provide species' distribution models for P. jauana based on current and future bioclimatic data. Future projections suggest that the geographic distribution of P. jauana will likely be severely affected, with ~79% of its suitable habitat being reduced by 2041-2060 and ~92% by 2061-2080. Prosthechea jauana could represent a flag species and an example of how climate change may affect the endemic Pantepui flora.

Preliminary placement and new records of an overlooked Amazonian tree, Christiana mennegae (Malvaceae).

Christiana mennegae is a phylogenetically enigmatic taxon and represents a case in point of a species whose presence escaped the radar of the Amazon lists and the Brazilian Flora project. Here we expand its distribution by adding new records from Peru and overlooked ones from Brazil. To investigate its phylogenetic placement in the Brownlowioideae, part of the rbcL gene of the plastid and the intergenic ITS2 region were sequenced. Macro- and micro-morphological investigation of features of C. mennegae using SEM of foliar, flower, fruit and seed structures are presented. A lectotype for the name is designated here. The morphology of trichomes revealed five types of trichomes ranging from glandular to branched and unbranched and we also report stomata on the seed surface for the first time in Brownlowioideae. Christiana mennegae and C. africana were recovered as sister species in the phylogenetic analysis, albeit with low to moderate support, and more species of this and closely related genera must be sampled and analyzed in order to obtain a clearer picture of the group's affinities and relationships. We provide an update of its conservation status from Vulnerable to Least Concern. We also highlight the need for investment in the digitization of biological collections, botanical capacity building at the local level and the importance of the availability of online literature to speed the study of Amazonian plant diversity.