Eugeniasarahchazaroi (Myrtaceae, Myrteae), a new species from the cloud forest of Mexico.

Following the description of Eugenianaraveana in 2016 from the cloud forest of the Cofre de Perote volcano, Mexico, the doubt about the existence of another unlocalized and sympatric species of Eugenia remained. After years of searching, the second endemic species of the Cofre de Perote volcano, Eugeniasarahchazaroi, is presented here. It belongs to the section Umbellatae, and is described, illustrated, and compared with E.naraveana and E.coetzalensis, recently described from Veracruz, the second state with the highest diversity of Eugenia in Mexico. The species is only known from the type locality and is classified in the Critically Endangered CR B1+B2(a,biii) category of the IUCN Red List conservation assessments.

The first epiphytic species of Valeriana in the world: Valerianarudychazaroi (Caprifoliaceae).

The currently known species of Valeriana are herbs, shrubs, small trees and vines. After 20 years without new species of Valeriana in Mexico, here is described and illustrated the first epiphytic species in the genus. The species was found growing on Quercusglabrescens trees of the cloud forests from central Veracruz in eastern Mexico. It is known and described from very few specimens in the type locality. The most morphologically similar Mexican species are the vines V.naidae and V.subincisa, it was compared. Conservation assessment classifies this species under the Critically Endangered CR B1+B2ab(ii,v) category of the IUCN Red List Criteria.

High proportion of cactus species threatened with extinction.

A high proportion of plant species is predicted to be threatened with extinction in the near future. However, the threat status of only a small number has been evaluated compared with key animal groups, rendering the magnitude and nature of the risks plants face unclear. Here we report the results of a global species assessment for the largest plant taxon evaluated to date under the International Union for Conservation of Nature (IUCN) Red List Categories and Criteria, the iconic Cactaceae (cacti). We show that cacti are among the most threatened taxonomic groups assessed to date, with 31% of the 1,478 evaluated species threatened, demonstrating the high anthropogenic pressures on biodiversity in arid lands. The distribution of threatened species and the predominant threatening processes and drivers are different to those described for other taxa. The most significant threat processes comprise land conversion to agriculture and aquaculture, collection as biological resources, and residential and commercial development. The dominant drivers of extinction risk are the unscrupulous collection of live plants and seeds for horticultural trade and private ornamental collections, smallholder livestock ranching and smallholder annual agriculture. Our findings demonstrate that global species assessments are readily achievable for major groups of plants with relatively moderate resources, and highlight different conservation priorities and actions to those derived from species assessments of key animal groups.