14Haseltonia 26: 14–22. 2019 Haseltonia 26: 14–22. 201914 Morphological and molecular diagnostic characters reveal a new species of Pachyphytum (Crassulaceae) Jerónimo Reyes Santiago1, Luis E. de La Cruz-López2*, Maria Kuzmina3, & Francisco Ver- gara-Silva1* 1 Jardín Botánico, Instituto de Biología, Universidad Nacional Autónoma de México. Circuito exterior s/n, Ciudad Universitaria, Copilco, Coyoacán, C.P. 04510, Ciudad de México, Mexico. 2 Posgrado en Ciencias Biológicas, Instituto de Biología, Universidad Nacional Autónoma de México. Av. Ciudad Universitaria 3000, C.P. 04360, Coyoacán, Ciudad de México, Mexico. 3 Centre for Biodiversity & Genomics, Biodiversity Institute of Ontario. University of Guelph, ON N1G 2W1, Ontario, Canada. * Authors for correspondence:
[email protected];
[email protected] Manuscript received 26th October 2018 Abstract: Pachyphytum viscidum (Crassulaceae: Saxifragales) is described as a new species to science. The speci- mens analyzed come from the Sierra de Santa Bárbara, Guanajuato, Mexico. Some morphological diagnostic characters for the new species are: sticky stems and leaves; dark green leaves; absence of wax on all their or- gans; and pale pink flowers. The new species is placed in the section Diotostemon of the genus, with pos- sible proximity to P. brevifolium and P. hookeri. DNA sequence analysis from the matK and rbcL chloroplast regions, as well as ITS2 nuclear loci, revealed the presence of molecular diagnostic sites which, in addition to the aforementioned morphological character states, further support the taxonomic description as well as future integrative taxonomy studies in Mexican Crassulaceae. Resumen: Se describe a Pachyphytum viscidum (Crassulaceae: Saxifragales) como una especie nueva para la ciencia. Los especímenes analizados provienen de la Sierra de Santa Bárbara, Guanajuato, México.