Abstract— Acalypha (Euphorbiaceae: Acalyphoideae) is a large, monophyletic genus distributed worldwide in tropical and subtropical regions, with a few species extending into temperate areas of southern Africa, Asia, and North and South America. We reconstructed phylogenetic relationships within the genus using DNA sequences from the plastid ndhF and trnL-F regions and the nuclear ribosomal ITS region, sampling 142 species to represent the geographic, morphologic, and taxonomic diversity with the genus, resulting in a 162 (158 in Acalypha) terminal and 3847 character combined dataset. Bayesian and maximum likelihood reconstructions based on the combined dataset yielded a tree with a generally well-supported backbone and several strongly supported clades. Our results strongly supported the monophyly of Acalypha subg. Acalypha as currently recognized but showed that A. subg. Linostachys and almost all other infrageneric taxa recognized in the most recent comprehensive classification of the genus were not monophyletic. We therefore propose a new subgeneric classification comprising A. subg. Acalypha, A. subg. Androcephala, A. subg. Hypandrae, and A. subg. Linostachys (s.s.). Our results also shed light on relationships within some species groups, including in what has been treated as a broadly defined A. amentacea, in which we recognize A. amentacea, A. palauensis comb. nov., and A. wilkesiana as distinct species. Bayesian ancestral state estimations based on the phylogeny of Acalypha demonstrated that inflorescence position and sexuality and habit show high homoplasy, especially within A. subg. Acalypha, and that inflorescence position and habit exhibit correlated evolution.

Antecedentes: La Sierra Madre Oriental es una Provincia Fisiográfica ubicada en el noreste de México con características geológicas, climáticas y edáficas distintivas. La flora de esta región aún no ha sido inventariada en conjunto. Preguntas: ¿Cuál es la diversidad florística de la Provincia Fisiográfica de la Sierra Madre Oriental? ¿Cuál es la afinidad geográfica de sus géneros? Sitio y años de estudio: Provincia Fisiográfica de la Sierra Madre Oriental. El trabajo se desarrolló desde agosto del 2012 a diciembre del 2020. Métodos: Se hizo una búsqueda exhaustiva de información en diversas fuentes como herbarios, bases de datos, trabajos florísticos y monografías. Para cada especie, se registró la vegetación, afinidad geográfica del género y endemismo. Resultados: Se registran 6,981 especies de las cuales 1,542 son endémicas. Las familias más ricas en especies son Asteraceae (1,000 especies), Fabaceae (495), Cactaceae (365) y Poaceae (328). Los bosques templados registran el mayor número de especies (2,906). Querétaro fue el estado con más especies (2,803), seguido de Coahuila (2,710) y Nuevo León (2,406). La Sierra Madre Oriental comprende una mayor cantidad de especies con géneros de afinidad geográfica boreal (2,742), seguidas por especies de afinidad tropical (2,020), especies endémicas de México (1,227), cosmopolitas (803) y de los desiertos del mundo (189). Conclusiones: La Sierra Madre Oriental alberga más de la cuarta parte de la flora vascular y un 13 % de las plantas endémicas del país. Es un área que reúne géneros de diferentes afinidades geográficas en su mayoría boreales, seguidos de tropicales y endémicos.

Background: Understanding the distribution and composition of ecosystems is fundamental for conservation efforts. Floristic and vegetational studies are especially important in nature reserves because they house biological resources and serve as natural laboratories. Questions: What species and vegetation types are present in the Zicuirán-Infiernillo Biosphere Reserve? What are the characteristics of the vegetation? Which species have local names, are endemic, and/or are of conservation concern? Data description: Vascular plants and vegetation of the Zicuirán-Infiernillo Biosphere Reserve. Study site and dates: The Zicuirán-Infiernillo Biosphere Reserve, Michoacán, Mexico; 1996-2020. Methods: Field work, herbarium work, and literature review. Results: Tropical deciduous forest is the most extensive vegetation. 125 families, 551 genera, and 1139 species are documented. The most diverse families are Fabaceae (165 species), Asteraceae (99), Poaceae (84), and Euphorbiaceae (77). Euphorbia (33), Ipomoea (25), and Bursera (21) are the most speciose genera. At least 13 species are endemic to the area. An additional 62 species are endemic when considering the “tierra caliente” of Michoacán and adjacent regions of the Balsas Depression in Jalisco and Guerrero. Twenty-one species are included in the NOM-059-SEMARNAT-2010, and 30 species have been assessed with a risk category in the IUCN Red List. Conclusions: The Zicuirán-Infiernillo Biosphere Reserve houses a diverse flora and extensive, well-conserved areas of tropical deciduous forest. It is hoped that this study stimulates further research on the biota of Reserve in order to achieve an integral understanding the area’s ecosystems and solidify conservation efforts.

Abstract—Serjania rosalindae and Serjania crucensis (Sapindaceae-Paullinieae), new species from the municipality of La Huacana, Michoacán, Mexico, are described, illustrated, and compared with closely related species. In addition, micromorphological features of the leaves, flowers, and pollen grains are investigated. A treatment of the endemic S. biternata from Guerrero is also included because it is a little-known taxon similar to S. rosalindae whose fruits were previously unknown. All of these taxa share capsules that are chartaceous to almost woody and septifragal, a fruit type otherwise uncommon within Serjania. The distinctive fruit morphology of these species is discussed in relation to other species of Serjania.

A taxonomic and nomenclatural review of the genus Croton (Euphorbiaceae) in the Mexican state of Michoacán is presented. Six sections and 20 species are here reported. The greatest diversity is in the Balsas Depression province, where at least 12 species occur. There is a strong tendency to thrive in tropical deciduous forest. An identification key is provided, and for each species, the following information is included: protologue citation, type information, habit, habitat, and elevation within the state, regional and global distribution, and phenology. Relevant synonyms are listed, as too are herbarium specimens. Lectotypes are designated for Croton draco, C. niveus, and C. calvescens. One species, Croton rojasii, is described as new and illustrated with photos. It is known only from tropical deciduous forest in the Zicuirán-Infiernillo Biosphere Reserve, at elevations from 400 to 700 m. It belongs to sect. Geiseleria and is remarkable because of the strongly unequal pistillate sepals, the larger of which becoming accrescent and exceeding the fruit.