Wednesday, December 14, 2022

[Botany • 2022] Diplostephium paposanum (Asteraceae: Astereae) • A New Species of Diplostephium from the Atacama Desert, Chile


 Diplostephium paposanum S.T.Ibáñez & Muñoz-Schick, 

in Ibáñez, Muñoz-Schick, Scherson & Moreira-Muñoz, 2022. 
Photographs by S. Ibáñez (A–E), A. Moreira (F).

Abstract
A new species, Diplostephium paposanum S.T.Ibáñez & Muñoz-Schick, sp. nov., is described for Chile, extending the southern distribution of the genus. Its position within the genus was confirmed by morphological and molecular data, discussed here. The new species was found in a coastal environment, new to the genus, and is geographically far removed from the other Chilean species, which are from the Andes. The formation where it occurs, known as lomas, acts as a biodiversity refuge in hyperarid environments. The presence of D. paposanum in this environment contributes to the evidence of a floristic connection between the Atacama Desert and the Neotropical Andes.

Keywords: Antofagasta, coast, fog oasis, lomas, molecular analysis, Paposo, taxonomy

Diplostephium paposanum in habitat
A general view of the type location “Quebrada Botija” B, C habit of individuals, growing on rocky ledges rooting on rock crevices D inflorescences on distal branches E lateral branchlets with terminal inflorescences F capitulum with fully unfolded style branches E, F note the colour differences on yellow disk florets with closed style branches and the mature purple disk florets with unfolded style branches.
Photographs by S. Ibáñez (A–E), A. Moreira (F).

 Diplostephium paposanum S.T.Ibáñez & Muñoz-Schick, sp. nov.
 
Diagnosis: D. paposanum is distinctive from most species of the genus because of its lack of tomentose or lanate hairs on its vegetative parts, including the adaxial side of the leaves. Additionally, D. paposanum has glandular succulent leaves, and short branches with leaves that are glabrate or scarcely puberulous in the apical section of long shoots.

Etymology: The epithet paposanum means “from Paposo”. Paposo is a small village located next to the foothills of the coastal cliffs which is the nearest urban centre to the species described.


 Sergio T. Ibáñez, Mélica Muñoz-Schick, Rosa A. Scherson and Andrés Moreira-Muñoz. 2022. A New Species of Diplostephium (Asteraceae, Astereae) from the Atacama Desert, Chile. PhytoKeys. 215: 51-63. DOI: 10.3897/phytokeys.215.89175

Resumen: Se describe una nueva especie para Chile, Diplostephium paposanum S.T.Ibáñez & Muñoz-Schick, sp. nov., extendiendo la distribución austral del género. Su posición dentro del género fue confirmada por datos morfológicos y moleculares, discutidos acá. La nueva especie se encontró en un ambiente costero, nuevo para el género, y está geográficamente alejada de las otras especies chilenas, que son de los Andes. La formación donde habita, conocida como lomas, actúa como refugio de la biodiversidad en ambientes hiperáridos. La presencia de D. paposanum en este ambiente contribuye a la evidencia de una conexión florística entre el Desierto de Atacama y los Andes Neotropicales.

Palabras clave: Análisis molecular, Antofagasta, costa, lomas, oasis de niebla, Paposo, taxonomía