@article {4067, title = {From open areas to forests? The evolutionary history of Philodendron subgenus Meconostigma (Araceae) using morphological data}, year = {2014}, abstract = {

Due to its wide distribution covering three of the largest Neotropical biomes, Philodendron subgenus Meconostigma is an interesting model to discuss the diversification of Neotropical plants. The aim of this study was to test a previous hypothesis that the Eastern and Southern species of P. subg. Meconostigma have plesiomorphic gynoecial structure while in Amazonian species they are apomorphic. To this end, we conducted an analysis of maximum parsimony with generalized frequency coding method using a matrix with 59 morphological characters and 90\% of the species of P. subg. Meconostigma. The phylogenetic reconstruction suggests that the subgenus is monophyletic and originates from open areas of Cerrado. Four morphological synapomorphies support the monophyly of the subgenus and seven synapomorphies support four minor clades within it. Our results also include characterization of three new gynoecial subtypes (A1, A2 and A3) within the subgenus. Subtype A2 (undeveloped stylar body with long stylar canals, absent central stylar dome, shallow compitum) is basal and represents the ancestral gynoecium in the group. These findings suggest that the balance between pollen uptake and accessibility of the locules were decisive to drive gynoecium evolution in the subgenus Meconostigma.

}, keywords = {Character analysis, Floral evolution, Gynoecium, Neotropics, phylogeny}, author = {Calazans, L.S.B. and Sakuragui, C.M. and Mayo, S.J.} } @article {4059, title = {Recognition of the genus Thaumatophyllum Schott - formerly Philodendron subg. Meconostigma (Araceae) - based on molecular and morphological evidence}, year = {2018}, abstract = {

Philodendron subgenus Meconostigma has been a well-circumscribed group since 1829. Members of this group are easily distinguished by diagnostic morphological characters as well as by a distinct ecology and geographical distribution. Based on molecular, morphological and cytological evidence, we propose the recognition of P. subg. Meconostigma as a distinct genus, Thaumatophyllum Schott. We also present the necessary new combinations, an emended key and some nomenclatural and taxonomic corrections regarding 21 names of Thaumatophyllum.

}, keywords = {chromosomes, molecular phylogeny, morphology, nomenclature, Philodendron, Thaumatophyllum}, doi = {doi: 10.3897/phytokeys.98.25044 }, author = {Sakuragui, C.M. and Calazans, L.S.B. and Loss-Oliveira, L. and Morais, E.B. and Benko-Iseppon, A.M. and Vasconcelos, S. and Schrago, C.G. and Mayo, S.J.} } @article {4057, title = {Floral Evolution of Philodendron Subgenus Meconostigma (Araceae)}, year = {2014}, abstract = {

Abstract
Elucidating the evolutionary patterns of flower and inflorescence structure is pivotal to understanding the phylogenetic relationships of Angiosperms as a whole. The inflorescence morphology and anatomy of Philodendron subgenus Meconostigma, belonging to the monocot family Araceae, has been widely studied but the evolutionary relationships of subgenus Meconostigma and the evolution of its flower characters have hitherto remained unclear. This study examines gynoecium evolution in subgenus Meconostigma in the context of an estimated molecular phylogeny for all extant species of subgenus Meconostigma and analysis of ancestral character reconstructions of some gynoecial structures. The phylogenetic reconstructions of all extant Meconostigma species were conducted under a maximum likelihood approach based on the sequences of two chloroplast (trnk and matK) and two nuclear (ETS and 18S) markers. This topology was used to reconstruct the ancestral states of seven floral characters and to elucidate their evolutionary pattern in the Meconostigma lineage. Our phylogeny shows that Meconostigma is composed of two major clades, one comprising two Amazonian species and the other all the species from the Atlantic Forest and Cerrado biomes with one Amazonian species. The common ancestor of the species of subgenus Meconostigma probably possessed short stylar lobes, long stylar canals, a stylar body, a vascular plexus in the gynoecium and druses in the stylar parenchyma but it is uncertain whether raphide inclusions were present in the parenchyma. The ancestral lineage also probably possessed up to 10 ovary locules. The evolution of these characters seems to have occurred independently in some lineages. We propose that the morphological and anatomical diversity observed in the gynoecial structures of subgenus Meconostigma is the result of an ongoing process of fusion of floral structures leading to a reduction of energy wastage and increase in stigmatic surface.

}, doi = {10.1371/journal.pone.0089701}, author = {Loss-Oliveira, L. and Calazans, L.S.B. and Morais, E.B. and Mayo, S.J. and Schrago, C.G. and Sakuragui, C.M.} }