A historical review, the circumscription problems and nomenclatural changes based upon a phylogenetic morphological analysis of the genus Centronia are presented. In this framework, four Andean species of Centronia are transfered to the genus Meriania (M. brachycera, M. haemantha, M. mutabilis and M. mutisii) and five new species related to this group (M. aguaditensis, M. arizae, M. silverstonei, M. sararensis and M. yalconensis) and three new subspecies of M. haemantha (subsp. chaponensis, subsp. orientalis and subsp. virolinensis) are described. The selection of lectotypes of M. haemantha and M. mutisii is made and four names Centronia eximia, C. pulchra, C. dichromantha and C. insignis, are considered synonyms. We argue that this group of nine species is a natural group witthin the genus Meriania, and present taxonomic revision.

The tribe Plantagineae (Lamiales) is a group of plants with worldwide distribution, notorious for its complicated taxonomy and still unresolved natural history. We describe the result of a broadly sampled phylogenetic study of tribe. The expanded sampling dataset is based on the trnL-F spacer, rbcL, and ITS2 markers across all three included genera (Aragoa, Littorella and Plantago) and makes this the most comprehensive study to date. The other dataset uses five markers and provides remarkably good resolution throughout the tree, including support for all of the major clades. In addition to the molecular phylogeny, a morphology database of 114 binary characters was assembled to provide comparison with the molecular phylogeny and to develop a means to assign species not sampled in the molecular analysis to their most closely related species that were sampled. Based on the molecular phylogeny and the assignment algorithm to place unsampled species, a key to sections is presented, and a revised classification of the tribe is provided. We also include the description of new species from North America.

Calyx and stamen characters have been used traditionally to separate genera and also to establish sections within genera in the tribe Merianieae (Melastomataceae). However, they have not been analyzed integrally from the point of view of homologies. In this study, a complete species list for the tribe is presented. We evaluated the variation of calyx and stamens characters. In the tribe Merianieae, there are 15 genera and 277 species; of these, 78% of the species was completely evaluated for these characters, and the other 22% was partially evaluated. Twenty-three characters were established; five of them were associated with the calyx and 18 with the stamens. In Merianieae, there are many combinations in the development of calyx lobes, the dorsal tooth, and the opening of the calyptra. The flowers are diplostemonous. Be found that in five of the genera (80% of the overall species of the tribe) there are nongeniculate stamen. We conclude that in the group with nongeniculate stamens, there was a merger of tissues of the connective and the filament. This fusion does not allow the stamens to untwist during anthesis. The variability of the characters is quantified in the most diverse genera, and the causes of problems of circumscription between the genera Centronia, Graffenrieda, and Meriania are documented. Los caracteres del cáliz y de los estambres se han utilizado clásicamente para diferenciar géneros y establecer secciones dentro de géneros en la tribu Merianieae (Melastomataceae), pero no se han analizado integralmente desde el punto de vista de homologías. Se estableció una lista completa de especies para la tribu y se evaluó la variación de los caracteres del cáliz y los estambres. En total se registran 15 géneros y 277 especies en Merianieae, el 78% de las cuales fueron evaluadas completamente y el resto de ellas parcialmente en lo referente a los caracteres estudiados. Se establecieron 23 caracteres, cinco asociados al cáliz y 18 a los estambres. En Merianieae se presenta gran variación en el desarrollo de los lóbulos y del diente dorsal del cáliz y en la apertura de la caliptra. Las flores son diplostémonas en todos los géneros. Se encontró que en cinco de los géneros (el 80% de las especies de la tribu) los estambres son no geniculados. Se plantea que la ausencia de geniculación en los estambres se originó por fusión de tejidos del conectivo y del filamento, que impide que los estambres se descontorsionen en la antesis. Se cuantifica la variabilidad de los caracteres en los géneros más diversificados y se documentan los problemas de circunscripción existentes entre los géneros Centronia, Graffenrieda y Meriania.

— Pachira condorensis is a new species collected in the white sand forests of the lowlands of the Cordillera del Cóndor in the Ecuadorian Amazon, a region with high levels of endemism. The new species is described and illustrated, and its affinities and differences from other morphologically close five-foliolate species of Pachira are discussed. It differs from these by having leaves with very short petioles, leaflets with yellow margins, adaxial surface of the leaflets being strongly glaucous and covered with scattered lepidote indument, and a globose-ovoid fruit with the apex strongly cuspidate. A key is also included to show the diagnostic characters that separate the new taxon from its mentioned relatives.

Matisia Bonpl. is a genus of Malvaceae (Matisieae) that is distributed from Nicaragua to Brazil. Twelve species of Matisia have been recorded in Panama. In this article, we add two species to the Panamanian flora, Matisia gentryi Fern.Alonso and M. tinamastiana A.Estrada & Cascante, and provide for both species full descriptions, images, a distribution map, taxonomic notes, and conservation status. Additionally, we provide an identification key for Matisia in Panama and propose the synonymization of Matisia sect. Tuberculatae Fern.Alonso under Matisia sect. Matisia.