Pachyphytum confusum (Crassulaceae), una especie nueva del suroeste del estado de Guanajuato, México

[摘要] Background and Aims: Pachyphytum(Crassulaceae) is a genus endemic to central Mexico, consisting of hanging and succulent plants that grow on cliffs and slopes. The taxonomic information ofPachyphytumis included in general works on Crassulaceae and a series of articles describing new species. At a regional level, it is included in the treatment of the family Crassulaceae for the Flora del Bajío y de regiones adyacentes. The aim of this work is to name and describe a new species ofPachyphytumbased on plants collected in the southeast of the state of Guanajuato. Methods:Excursions were realized to one of the localities in the Sierra de Pénjamo from where the plant was registered, as well as to the type locality ofPachyphytum machucae . Descriptions of the collected plants and a comparative table were prepared, and the literature was searched for morphologically similar species.Key results: Pachyphytum confusumis proposed as a species new to science and is compared withP. machucaeandP. glutinicaulewhich it resembles morphologically. The conservation status of Vulnerable (VU) is assigned.Conclusions:Despite the fact thatPachyphytumconsists of 21 especies, it is difficult to interprete their relationships; in its last revision two sections were considered;PachyphytumandDiotostemon ; the new species belongs to the first one. The specimens collected in the Sierra de Pénjamo were previously confused withP. machucae , but their comparison showed significant differences in order to consider them as a distinct species.Pachyphytum glutinicaule , another species which it resembles, has a corolla longer than the calyx; however, both species show differences in its petals, bracts and leaves. The inconsistency of the infrageneric classification is discussed in several publications, which is emphasized by the discovery ofPachyphytum confusum .

[学科分类] 植物学

[关键词] Diotostemon;Guanajuato;Pachyphytum glutinicaule;Pénjamo