No abstract

Artículo de publicación ISIA 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 groupsConsejo Nacional de Ciencia y Tecnologia 000000000011820

Th(^ nK)n()|)livtv and pin lot^cnctic relati()nslii|ts iif the Irihe Kii|)h^nized jicneia. subgenera, and sections within the Euplunbieae and 1 oulj^roup taxa from \\\v tribe lli[)[>otnaneae (Knpliorbiac(^ae). I^'>ll' tl><' I 1'^ ^>'i*' ^^^fhV aiial}ses suppitrl the innnophvly of Kuphorbieae in adiy Ijefore the !>reaku|) of (ittudwanaland. at whiih time the major lineages of subtril)e ' We are extremely gratehil to all those who have assist^^l with this research. In particular we thank Susan (barter, J. Travis Columbus, FdizalxMh Kriar. Victoria llnllowell. (,ordnn MePherson. and Oady Webster for critically reviewing the manuscri]tt. For permission to examine tluir c(j|lectiotr^ and to sam[)lc herbarium uialerial, we thank the curators and staffs at MUZ. CAS. I)A\. FNCB. K CB. K. MO, NY. USA. SCO, Sl\ and TEX. The following institntions ami inilividuals extended assistance by permitting access to their living collections: Dylan llannon; Chuck Hanson of Arid bands (weenhouses; Mark Mayfield; Meetia Singh; S<'ymonr bindf^n; John Trager and Jot-ChMuents of the llnntington Botanical Carden; I'rs Eggli of Snkkulenten-Sammlung /ihich: and Herman Schwartz. Cordon McTherson and Sebastian Teillier collected material (A' .W'of^iiillaandnid itcopalnt and Kupliorlmi grtfiKiitui, respecti\ ely. Fieldwork, herbarium visits, and laboiatory use and materials were made possible by the giMu-rous support of the Andrew W. M<'llon Fonnihition, the American Socii'tv of IMarit Taxonomists, the Howard and Phoebe Brown Scholarship, and the Hardman Native FMant Besearch Award. I.anren Baz jirovided ITS secjucnees for Cluimui'syce degcneri, C, hyper'uljoiia, and C prnslnita. Kenneth Wnrdack gave useful information about outgroup selection. We are Indebted to ihe staff and graduate students at tlte Hancho Santa Ana Botanic Carden for enconragement and support, especiall} Eric Uoalson for his (n)ntinuous hclji and ad\ice. M^ancho Santa Ana Botanic C...

Opuntioideae are a diverse subfamily of Cactaceae with significant diversity of form and habitat and wide distribution throughout the New World. Nuclear ribosomal ITS and chloroplast trnL-trnF region DNA sequence-based phylogenetic analysis of Opuntioideae derived from Bayesian methods is presented. This analysis supports the following relationships: Opuntioideae are monophyletic; the subfamily is made up of four major lineages (Maihueniopsis-like species, Pterocactus, other terete-stemmed species, and flat-stemmed species). The two deepest lineages (including most species of Maihueniopsis and all Pterocactus) are marked by diminutive, succulent, often geophytic habit and are leafless at maturity. These analyses suggest that Opuntioideae have geographic origin in west-central South America. Generic circumscription is considered in the context of the recovered relationships. Maihueniopsis is recovered in multiple lineages. Many currently accepted genera may be para-or polyphyletic.

Nuclear ribosomal internal transcribed spacer (ITS) DNA sequences are used to estimate the phylogeny of 53 members of Polemoniaceae, representing all but two genera of the family. Fitch parsimony analysis of equal-weighted nucleotide sites result in 1080 minimal-length trees. However, when alignment-ambiguou s positions are removed and an II: 10 transition to transversion weighting is imposed only eight trees are found. These data are used to address two issues: I) patterns of diversification in Polemoniaceae, and 2) the circumscription and monophyly of the genus Cilia. Although the monophyly of Polemoniaceae is well supported, relationships inferred among the earliest diverging lineages are altered by character weighting, treatment of indels, and taxon inclusion. In spite of the lack of reliable resolution at the basal nodes, ITS data provide evidence that Cilia, as currently interpreted, is polyphyletic and comprises at least five independent lineages.