Encyclia comprises over 150 species of orchids that occupy mainly seasonally dry habitats in tropical and subtropical America and are usually restricted to one or a few ecoregions. To determine whether species found in the same or neighboring ecoregions are closely related, we sampled more than 50 taxa, with an emphasis on species found in Mexico and Central America. We evaluated five DNA markers for their phylogenetic utility: the nuclear low copy gene PHYC, a plastid spacer region trnL‐F, a fragment of the plastid ycf1 gene, rpl32‐trnL, and the internal transcribed spacer (ITS) region of nuclear ribosomal DNA; we sampled only the last three markers for the main analyses based on an assessment of phylogenetic informativeness. We analyzed plastid regions and ITS separately in phylogenetic inference using a variety of methods, as we found strong incongruence between them, according to the ILD test. We also estimated clade ages using a relaxed molecular clock with indirect calibrations based on a larger taxonomic sampling. Encyclia is a monophyletic genus that originated ca. 12.43 Ma (10.55–14.25 Ma) ago, and has undergone several recent evolutionary radiations. We found a strong association between phylogenetic relationships and the geographic distribution of species and clades in the Caribbean, Central American, and the Pacific coast of Megamexico. Several groups of Encyclia occur in the latter region, the most species‐rich being the E. meliosma complex, which is restricted to the Pacific slope of Mexico from north of the Isthmus of Tehuantepec up to Sonora.

Pseudocercospora (previously known as Mycosphaerella) fijiensis causes black Sigatoka disease in banana (Musa spp.) and is considered to be the most devastating pathogen of this crop worldwide. To improve knowledge of its evolutionary patterns, this study determined the genetic variability of populations from two regions of Mexico: Central Pacific (Colima and Michoacan) and Southern (Chiapas, Tabasco and Oaxaca), using 10 simple sequence repeat (SSR) loci and the MAT‐specific PCR assay. Both mating types were present in all regions under study, with frequencies of 63% MAT1‐1 and 37% MAT1‐2. The SSR markers showed an average of three alleles per locus, resulting in 34 alleles in total. The genetic diversity (HT) was 0.3308, but at the local level (HS) ranged from 0.0976 (Colima) to 0.2228 (Oaxaca). However, the genotypic diversity was usually high (H′ > 2.4, S > 0.89). Cluster analysis grouped the isolates into five clusters with high statistical support (au > 80%), suggesting a geographic organization of the genetic variability of P. fijiensis; AMOVA, the minimum spanning tree and the population structure analysis supported this result, and all data indicated that the major genetic differences were between the different populations under analysis. Thus, the high level of genetic variability in P. fijiensis is attributed partly to a high rate of sexual reproduction, and also to a strong evolutionary capacity coupled with isolation due to limited genetic flow between distant populations. Both possibilities could be playing a relevant role in population differentiation of the pathogen.

Antecedentes y Objetivos: Lysiloma es un género neotropical de la familia Fabaceae que comprende ocho especies, seis de las cuales se distribuyen ampliamente en México y dos más que ocurren en las Antillas y La Florida. Lysiloma es frecuente en los bosques secos de Megaméxico. Un estudio filogenético previo incluyó tres especies de Lysiloma y Hesperalbizia occidentalis. Ambos géneros están estrechamente relacionados, pero su divergencia tiene un apoyo débil. Nuestros objetivos fueron probar la monofilia del género, evaluar las relaciones de grupo hermano dentro del género y estimar los tiempos de divergencia. Métodos: Se realizó un análisis filogenético basado en caracteres morfológicos, marcadores moleculares (ETS, matK y trnK), así como un análisis combinado (morfología + moléculas). Las matrices de datos se analizaron tanto individualmente como concatenadas (enfoque de evidencia total) con inferencia Bayesiana y máxima parsimonia. Además, los tiempos de divergencia molecular se estimaron a partir del conjunto de datos ETS con un modelo de reloj bayesiano relajado lognormal no correlacionado. Resultados clave: El análisis morfológico respalda la monofilia del Lysiloma con Hesperalbizia como grupo hermano. Sin embargo, los análisis moleculares individuales y combinado no proporcionan resolución para aclarar las relaciones entre Hesperalbizia occidentalis, Lysiloma sabicu y el núcleo de Lysiloma. El análisis de evidencia total (incluida la morfología) respalda la monofilia de Lysiloma, pero con un bajo soporte. Según nuestro modelo de reloj molecular, el clado Lysiloma+Hesperalbizia se separó de otros miembros de la tribu Acacieae+Ingeae hace unos 32 millones de años y la diversificación del núcleo del Lysiloma se produjo a lo largo del Mioceno.Conclusiones: Lysiloma+Hesperalbizia es un clado de divergencia temprana de las tribus Acacieae+Ingeae. Existen suficientes diferencias morfológicas para reconocer ambos linajes. Los caracteres morfológicos utilizados informalmente para la delimitación taxonómica parecen haber evolucionado de manera homoplásica. El clado de Lysiloma y Hesperalbizia se separó de otros miembros de la tribu Acacieae+Ingeae en el Oligoceno, pero la diversificación del núcleo del género coincidió con la expansión del bosque seco a principios del Mioceno.

Two new species of Encyclia are proposed, E. silverarum and E. parkeri. Both species belong in the Encyclia chloroleuca complex, conformed also by E. chloroleuca, E. elegantula, and E. peraltensis, among others. Encyclia silverarum is known only from Panama. This species is very similar to Encyclia chloroleuca, but it is distinguished by the color of its sepals and petals (pale green-yellowish brown) and the falcate and proportionally short (<0.60 vs. >0.80 cm long) side lobes of the labellum. Encyclia parkeri, known only from Colombia (Department of Valle del Cauca), also is similar to Encyclia chloroleuca; however, it is distinguished by its flowers with olive-green to ocher petals and sepals, labellum creamy white, with the central lobe with many keels (at least three), all warty and usually slightly tinged red-purple.

A synopsis of the Encyclia ambigua complex, a member of the E. ceratistes clade, is presented. It is composed of three species, namely E. ambigua, E. trachychila, and E. dressleri. These taxa are restricted to the southern part of Megamexico in Mexico, Guatemala, Honduras, and Nicaragua and occur mostly in oak-pine or broadleaf evergreen forests, or more rarely, in tropical dry forests at elevations of (600–)1,250–1,700(–2,000) m. The recently described Encyclia alborubra is treated as a synonym of E. ambigua. Iconography pertinent to the understanding of the species, relevant discussion, and a key to the taxa involved are provided. In addition, we provide notes on Encyclia virens, attempting to decipher this nomenclatural puzzle, and on Epidendrum alatum Batem., to present a protologue that predates the one that is usually cited.