The Simaba guianensis complex in northers South America

Abstract

With additional data from specimens not studied by previous workers, the confusing Simaba guianensis compex was re-analized. Simaba polyphylla is recognized as a distinct species and two subspecies of S. guianensis are maintained. Simaba polyphylla, S. guianensis ssp. guianensis, and S. guianensis ssp. ecaudata are keyed, described, and illustrated and specimens examined are cited for each. Specimens of S. guianensis ssp. ecaudata show great morphological diversity but can be separeted into three groups. Further collecting may provide information that shows these groups to be worthy of separate taxonomic status.

Molecular Phylogeny of the Tree‐of‐Heaven Family (Simaroubaceae) Based on Chloroplast and Nuclear Markers

“…Simaba is distinct from Simarouba, based on its perfect flowers with capitate or lobed stigmas and typically opposite leaflets, as compared to the unisexual flowers, long divergent stigmas, and offset leaflets of Simarouba (Cronquist 1944b(Cronquist , 1944c(Cronquist , 1944d. Simaba consists of two subclades, one of which corresponds to Engler's (1874) section Tenuiflorae (containing the Simaba guianensis complex; Thomas 1985;Franceschinelli and Thomas 2000), which is characterized by small flowers with puberulent petals and is found primarily in the moist Amazon basin (Cronquist 1944c). The second subclade consists of sections Floribundae and Grandiflorae; these are larger-flowered species with villous-tomentose petals, found primarily in the drier regions of southern and eastern Brazil and Paraguay (Cronquist 1944c).…”

“…However, only Simaba cedron was sampled from section Grandiflorae, so more taxa are needed to assess the monophyly of the two sections. The variable positions of accessions of Simaba guianensis and low PP and BS values within section Tenuiflorae reflect the difficulties of delimiting species and subspecies in this clade (Thomas 1985; W. W. Thomas, personal communication). More taxa and a more rapidly evolving gene region will help to clarify relationships in this group.…”

Flora of the Reserva Ducke, Amazonas, Brazil: Simaroubaceae

“…The problematic S. guianensis complex has been the subject of interest of several botanists, since Engler's monograph (Engler 1874). Here we roughly follow the latest review of this species complex, provided by Thomas (1985), including a broad morphological variability, particularly in habit, leaf features and ecological ranges. Further studies are necessary to achieve a better understanding of the limits of this species and its putative infraspecific taxa.…”

Phylogeny and systematics of Simaba Aubl. (Simaroubacea)

“…Its species may be treelets to tall trees in the Amazon forests or in moist to seasonal areas along the Atlantic forest The main studies on morphology and taxonomy of Simaba are the monograph by in Flora Brasiliensis, the anatomical study by , the revision by , the revision of South American species by , and scattered contributions on new species and synonyms (e.g. Thomas 1984Thomas , 1985Franceschinelli & Thomas 2000). From the 50 binomials already proposed in Simaba, just a half are currently accepted as correct.…”

“…This broad circumscription of Quassia, however, was never embraced by most botanists, and in the Neotropics Simaba, Simarouba, and Quassia were maintained as distinct genera in regional floras and monographs (e.g. Porter 1973;Thomas 1985Thomas , 1990Pirani 1987Pirani , 2015Arrázola 1993;Thomas & Franceschinelli 2005;Devecchi & Pirani 2015, 2016Devecchi et al 2016), including the latest revision of Simaba . With the advent of molecular data, the broad circumscription of Quassia suggested by Nooteboom (1962a) was also refuted by the phylogenetic study of Simaroubaceae by , in which the sectional components of Quassia s.l.…”