Wednesday, November 8, 2017

[Botany • 2017] Reestablishment of Mansoa ventricosa (Bignonieae, Bignoniaceae) Based on Molecular and Morphological Data


  Mansoa ventricosa A.H. Gentry

 Francisco & Lohmann, 2017

Abstract

Pachyptera ventricosa is a rare and poorly known species of liana that occurs in wet forests from the state of Pará, in Brazil. This species is characterized by features that are diagnostic of four genera within tribe Bignonieae: Mansoa, Martinella, Pachyptera, and Tanaecium. The currently recognized P. ventricosa was originally described in Mansoa, but subsequently transferred to Pachyptera based on morphological similarities. In this study, we use a combination of molecular and morphological data to evaluate the current placement of P. ventricosa. We conduct a broad scale molecular phylogenetic study based on 114 sequences of ndhF and PepC representing 112 taxa and members of all genera recognized in Bignonieae. In addition, we also conduct detailed morphological studies of selected characters. Our molecular phylogenetic study indicates that the currently recognized Pachyptera ventricosa is more closely related to members of Mansoa than to Pachyptera. New morphological data corroborates the molecular phylogenetic placement indicating that this species is indeed best placed within Mansoa. We here propose the reestablishment of Mansoa ventricosa, and show the detailed description for this species, along with new distribution information, and the first illustration for this taxon.

Keywords: Amazonian biota, Brazilian flora, generic circumscription, Eudicots


Inflorescence of Mansoa ventricosa.
Photo A by Annelise F. Nunez.

Mansoa ventricosa A.H. Gentry (1979 [1980]: 783). 
Pachyptera ventricosa (A.H. Gentry) L.G. Lohmann (2014: 456) 

Type:— BRAZIL. Pará: Along the Belém-Brasilia highway, km 345, 9 August 1956, B. Maguire et al. 56083 (holotype, MO-2232816!; isotypes, COL-110166 not seen, MG-136673, NY-328882!, US-3189002 image!).

Pollination:— The corolla morphology is classified as a variant of the Martinella type (Gentry 1974), and is likely associated with bat pollination (Alcantara & Lohmann 2010, Machado & Vogel 2004). This species shares tricolpate coarse reticulate pollen grains with Martinella obovata (Gentry & Tomb 1979) suggesting convergent evolution of pollen type. Such convergence has also been observed in other floral traits such as the purple colored flower, thick corolla texture, open mouth, and subexserted anthers. 

Distribution and habitat:— Mansoa ventricosa is endemic to Northeastern Brazil (Maranhão, Pará), where it occurs in wet evergreen forests (Figure 5). Prior to this work, this species was only known from the holotype collected in the Brazilian state of Pará, a paratype collected in the Brazilian state of Maranhão (G.T. Prance 58978; UB and NY), and one collection from 1980 (D.C. Daly 774; MG, MO, and NY). Two additional specimens were collected during our fieldwork in Pará, (Brazil), expanding the distribution of this species to Santarém and Belterra.

Taxonomic notes:— Mansoa ventricosa is easily recognized by a combination of cylindrical and striated branchlets with “V” shaped interpetiolar clusters of glands, subulate prophylls of the axillary buds, and leaflets with nectaries grouped at the base of the abaxial surface. Reproductive characters that can help in its identification are the thyrsoid inflorescences, calyx with patelliform glands clustered next to the margin, corolla campanulate, with tube light purple, densely puberulous outside, with patelliform glands at the upper portion of the apex tube, androecium subexserted with yellow anthers, and exserted gynoecium. 


Jessica Nayara Carvalho Francisco and Lucia G Lohmann. 2017.  Reestablishment of Mansoa ventricosa (Bignonieae, Bignoniaceae) Based on Molecular and Morphological Data. Phytotaxa. 327(2); 141–156. DOI: 10.11646/phytotaxa.327.2.3


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