Herbarium specimens of wild Mexican Leguminosae with ethnobotanical information are an important resource for understanding human–legume interactions. The 525 useful legume species registered in Mexico’s National Herbarium (MEXU) were analyzed using a hierarchical method and represented in dendrograms. Of these, 244 species noted a single use, while 281 species reported two or more uses. Plants applied for medicinal purposes registered the greatest number of species (351 spp.), followed by those employed as animal food (205 spp.), material sources (197 spp.), environmental modifiers (139 spp.), and food and food additives (119 spp.). This study also suggests that a greater number of uses is concentrated in closely related species-rich taxa rather than in less diverse groups, and that certain uses are clustered in phylogenetically related groups. Of particular interest are multipurpose shrubs and trees managed as living fences that satisfy a variety of needs in rural areas. This diversity of legume resources used by Mexican people may be advantageous in the planning and management of conservation areas, since the diversity, ubiquity, and economic importance of some of species have promoted overuse and destruction.

As part of the Fabaceae project of northeastern Mexico and based on field work, collection of botanical samples over the past 37 years, and reviewing botanical materials in national and international herbaria, the diversity of legumes of the subfamilies Caesalpinioideae (excluding tribe Mimoseae), Cercidoideae, and Detarioideae in northeastern Mexico has been recorded. New nomenclatural changes in tribes and genera of the subfamily Caesalpinioideae found in the new scientific bibliography are included. The subfamily Caesalpinioideae (excluding the tribe Mimoseae) includes five tribes: tribe Caesalpinieae, with eight genera (Caesalpinia, Coulteria, Denisophytum, Erythrostemon, Guilandina, Hoffmannseggia, Haematoxylum, and Pomaria) and 21 species; tribe Cassieae with three genera (Cassia, Chamaecrita, and Senna) and 28 species; tribe Ceratonieae with one genus (Ceratonia) and 1 species; tribe Gleditsieae with one genus (Gleditsia) and 1 species. The subfamily Cercidoideae includes two genera (Bauhinia and Cercis) and eight species, and the subfamily Detarioideae includes only one genus and one species (Tamarindus indicus). The total flora of these three subfamilies comprises 18 genera and 63 species, including 56 native species and 7 exotic ones: Bauhinia variegata, Cassia fistula, Ceratonia siliqua, Delonix regia, Erythrostemon gilliesii, Senna alata, and Tamarindus indicus. Endemism includes a total of 22 species and nine infraspecific categories.

Antecedentes: A pesar de su gran diversidad y la grave amenaza a la que están expuestos, los pastizales templados han recibido escasa atención. Pregunta: Este estudio examina la biodiversidad de paisajes y taxonómía en los pastizales templados de Oaxaca. Especies estudiadas: Flora vascular. Sitio de estudio y fechas: Los pastizales volcánicos (PV), calcícolas (PC) y sabanas de encino (SE) del norte de Oaxaca entre 2021 y 2022. Métodos: Tras delimitar los tres sistemas realizamos colectas, describimos la vegetación y discutimos su estado de conservación. Resultados: Los PV y PC son los más diversos. En los PV, la diversidad se ve favorecida por el pastoreo, cuya ausencia promueve la invasión por plantas exóticas y pérdida de especies. Los PC han sufrido graves impactos debido a la agricultura, el sobrepastoreo y la plantación de pinos. Las SE son las menos diversas, aunque las menos muestreadas, y albergan especies importantes para su conservación. En total se documentaron 857 especies de plantas vasculares (aunque los datos indican que esto es una subestimación considerable), siendo el segundo pastizal más diverso de Norteamérica y comprendiendo 25 % de las especies del Valle de Tehuacán-Cuicatlán en 0.7 % de su superficie. Las familias más diversas fueron Asteraceae, Poaceae, Fabaceae, Lamiaceae y Euphorbiaceae. El 37 % de las especies son endémicas de México, algunas especies microendémicas (3) y 26 amenazadas. Además, se descubrieron tres nuevos taxones. Conclusiones: Nuestros resultados subrayan la importancia de conocer y conservar las praderas intertropicales templadas de México ante la rápida destrucción que enfrentan.

Background: Although there is a compendium of species diversity for the Flora of North America, including the Fabaceae, many legume species were excluded. Therefore, this study fills this information gap and updates the systematics and nomenclature of this group in accordance with the new changes proposed by the LPWG. Objective: To update the taxonomy and to document the species richness and endemism of the tribes Desmodieae, Millettieae, Psoraleeae, Robinieae, Sesbanieae, Sophoreae, and Trifolieae (Fabaceae) in northeastern Mexico. Methods: The study is based primarily on the botanical specimens collected by some of the authors during the last 45 years and the review of national and international herbaria, where legumes from northeastern Mexico are deposited. Results: Richness—A total of 7 tribes, 22 genera, and 69 species of legumes were recorded, and distributed as follows: Desmodieae (four genera, 29 species; Millettieae, three genera, nine species); Psoraleeae (two genera, four species); Robinieae (five genera, eight species); Sesbanieae (one genus, two species); Sophoreae (four genera, seven species), and Trifolieae (three genera, nine species). Endemism—A total of 15 of the 69 species recorded in the northeastern region are endemic to Mexico (22%). Five of the seven tribes under study have endemic taxa in the northeastern part of the country: Desmodieae (two species), Robinieae (two species), Sophoreae (three species), and Trifolieae (one species). Desmodium is the genus with the highest number of endemic species (4), followed by Dermatophyllum with two species. Conclusions: The diversity of legume species in the studied tribes in northeastern Mexico is high; almost a quarter of the species studied are endemic to this region. Therefore, it is necessary and a priority to create policies and appropriate practical measures for the conservation of the ecosystems where these taxa thrive.