Wednesday, December 6, 2023

[Botany • 2019] Aeschynomene chicocesariana (Leguminosae: Papilionoideae) • A Striking New Unifoliolate Legume Species from the Brazilian Chapada Diamantina and its Phylogenetic Placement in the Dalbergioid Clade


Aeschynomene chicocesariana D.B.O.S.Cardoso & G.Ramos,  

in Cardoso, Ramos, São-Mateus et de Queiroz, 2019.

 Abstract
Unifoliolate leaves are relatively rare in the species-rich dalbergioid clade of papilionoid legumes (Leguminosae, Papilionoideae). For the pantropical, diverse genus Aeschynomene (ca. 180 species), the only known record of unifoliolate species described so far is the savanna-inhabiting A. simplicifolia from Chapada dos Veadeiros in Goiás, Brazil. The current work provides a description, illustrations, and a distribution map of another unifoliolate species, Aeschynomene chicocesariana , which was newly discovered in the rupestrian grasslands of Chapada Diamantina in Bahia, Brazil. Bayesian phylogenetic analyses of DNA sequence data (nuclear ribosomal ITS/5.8S and the plastid genes matK and trnL intron) have unequivocally placed A. chicocesariana with the rest of Aeschynomene species that are traditionally placed within Aeschynomene sect. Ochopodium. This result agrees with the shared morphology of A. chicocesariana and members of that section.

Keywords: Leguminosae; Ochopodium; Papilionoideae; taxonomy



General morphology of Aeschynomene chicocesariana.
A. Habit. B. Detail of the branch showing the non-peltate, basifixed stipules and unifoliolate leaves appressed against the erect stem. C. Detail of the terminal raceme to show the flowers. D. Indehiscent, single-seeded loments with the basalmost aborted article; note that the loments are borne on a very long stipe.
All photographs by Domingos Cardoso, from the specimen Cardoso et al. 3640 (HUEFS) at the type locality.

Aeschynomene chicocesariana D.B.O.S.Cardoso & G.Ramos, sp. nov.


  Domingos Benício Oliveira Silva Cardoso, Gustavo Ramos, Wallace Messias Barbosa São-Mateus and Luciano Paganucci de Queiroz. 2019. Aeschynomene chicocesariana, A Striking New Unifoliolate Legume Species from the Brazilian Chapada Diamantina and its Phylogenetic Placement in the Dalbergioid Clade. Systematic Botany. 44(4); 810 - 817. DOI:  10.1600/036364419X15710776741530