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| Desmopsis ibarrarum G.E. Schatz ex Ortiz-Rodr., in Ortiz-Rodriguez, 2022. |
Abstract
Background and Aims: A frequently collected species of Desmopsis (Annonaceae) in Mexico has remained indeterminate for more than 30 years. Its floral characteristics are similar to those present in the Asian genus Guamia (now Meiogyne), and for many years it has been named “Guamia mexicana”, but not formally described. Recently, it was shown that “Guamia mexicana” is phylogenetically related to Desmopsis and Stenanona and not to Guamia. However, and despite being frequently collected, its taxonomic status has not been clarified. Here, the phylogenetic relationships and the morphological and ecological characteristics that distinguish “Guamia mexicana” from other species were studied. As a result, this new species is herein described.
Methods: The new species was recognized using the unique combination of features through comparisons with morphologically similar species and a literature review. Its pollen characteristics were analysed using scanning electron microscopy. Its phylogenetic relationships were determined based on previously published phylogenies. Lastly, its conservation status was tentatively assessed by calculating extent of occurrence (EOO) and area of occupancy (AOO) using the GeoCAT tool and applying the IUCN Red List categories and criteria.
Key results: A new species of Annonaceae endemic to Mexico, namely Desmopsis ibarrarum, is described and illustrated. It is distinguished from other Desmopsis species by the combination of long and cylindrical fruits with many seeds, with a hard and woody testa and densely covered by very small sericeous hairs (velvety), glabrous leaves with percurrent tertiary venation, the absence of leafy bracts on the pedicels, the morphological differentiation of internal and external petals, and the partial fusion of the sepals.
Conclusions: Desmopsis ibarrarum is only closely related to Desmopsis dubia and both species are here considered members of a particular lineage within the Desmopsis-Stenanona clade, the “Desmopsis dubia group”.
Key words: Chiapas, IUCN Red List, karst forests, Neotropical region, pollen grains, tribe Miliuseae.
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| Desmopsis ibarrarum G.E. Schatz ex Ortiz-Rodr. A. main trunk bark; B. upper leaf surface; C. lower leaf surface; D. inflorescence with solitary, yellow flower; E. lateral view of the flower, the surface covered with sericeous hairs can be appreciated; F. front view of the flower, note the differentiation in the position and shape of the petals whorls; G. H. infructescences, the whitish or yellowish color of the fruits is due to the fact that they are densely covered by very small sericeous or golden, persistent hairs; I. open fruit, the thick and woody wall can be observed, as well as the numerous discoid seeds. |
Desmopsis ibarrarum G.E. Schatz ex Ortiz-Rodr., sp. nov.
Similar to Desmopsis dubia in the leaves with percurrent tertiary venation, short-pedicellate flowers without leafy bracts at base of pedicels, food bodies at base of inner petals, the partially fused sepals, and the cylindrical fruits with hard, woody testa, but different in its glabrous leaves above and below, flowers with longer petals, and smaller fruits with fewer seeds.
Etymology: the specific epithet honors Guillermo Ibarra Manríquez and his wife Guadalupe Cornejo Tenorio (“Los Ibarras”), two prolific Mexican botanists who for many years have contributed to the knowledge of the Mexican flora, in particular to the region of Los Tuxtlas in Veracruz.
Andrés Ernesto Ortiz-Rodriguez. 2022. Naming the Long-known: A New Species of Desmopsis (Annonaceae) endemic to Mexico. Acta Botanica Mexicana 129: e2110. DOI: 10.21829/abm129.2022.2110
