Butia capitata (Mart.) Becc. lamina anatomy as a tool for taxonomic distinction from B. odorata (Barb. Rodr.) Noblick comb. nov (Arecaceae)

Abstract

Butia capitata (Mart.) Becc. lamina anatomy as a tool for taxonomic distinction from B. odorata (Barb. Rodr.) Noblick comb. nov (Arecaceae) BRUNO ABSTRACTThe distinction between Butia capitata and B. odorata is based only on a few morphological characteristics, therefore there is a need for additional studies for supporting the separation of the species. As lamina anatomy characteristics are relevant in circumscribing Arecaceae taxa, this work aimed to describe B. capitata lamina anatomy and compare it with B. odorata. Samples from the middle portion of the pinnae were collected and processed in accordance with standard plant anatomy techniques. The epidermis is uniseriate and composed of a thick cuticle and epicuticular waxes into like hooked filaments. The subsidiary cells that arch over the guard cells are located at the hypodermis. The mesophyll is isobilateral and compact. The vascular bundles are collateral with a sclerenchymatic sheath extension that reaches the hypodermis. The stegmata cells have spherical and druse-like silica bodies. The midrib faces the adaxial surface with a thick fibrous layer surrounding the vascular bundles adjacent to the chlorenchyma. The stratified expansion tissue is on the abaxial surface, within the boundary between the mesophyll and midrib. Raphides are only found in B. capitata. Small bundles of the midrib fully surround the fibrous cylinder only in B. odorata. These characteristics are diagnostic and useful for supporting the proposed separation.

Does leaf anatomy aid in species identification of Butia (Arecaceae)?

“…Similar to B. paraguayensis , B. capitata seems to be a highly variable species ( Glasmann 1970 ), and a broader taxonomic study is fundamental to better elucidate any questions regarding this group. It is worth mentioning that the anatomical characteristics observed in the present study in B. capitata (presence of raphides, midrib format, expansion tissue, accessory bundles and others) were similar to those of B. odorata and previously reported by Sant’Anna-Santos et al (2015) . Moreover, we analysed samples from other populations of B. capitata , indicating reliability in the use of these data presented here.…”

“…Butia catarinensis and B. odorata stand out for presenting accessory bundles surrounding the vascular system of the midrib, which do not occur in B. eriospatha . This character has been previously observed in B. odorata ( Sant’Anna-Santos et al 2015 ). Butia odorata has natural populations occurring near to B. catarinensis and disjunct by a narrow strip of seacoast ( Noblick 2010 ).…”

“…However, this character is helpful to differentiate species that sometimes are confused. Among all the evaluated traits, raphides may show a few major advantages: convenience and low cost for obtaining the data, easy visualization and reliability for species distinction, having already been used successfully to discriminate between other morphologically similar Butia ( Sant’Anna-Santos et al 2015 ).…”

“…For the light microscopy studies, samples were previously softened for 12 h in a solution of 10 % ethylenediamine, as described by Sant’Anna-Santos et al (2015) . Thus, samples were sectioned on a microtome table (model LPC, Rolemberg e Bhering Comércio e Importação LTDA., Belo Horizonte, Brazil) with a disposable razor blade.…”

“…Because of this, taxonomy of Arecaceae traditionally has also been based on anatomical aspects of the organs, mainly of the leaf blade ( Tomnlinson 1961 ; Tomnlinson et al 2011 ; Noblick 2013 , 2014 ; Martins et al 2015 ; Sant’Anna-Santos et al 2015 ; Pinedo et al 2016 ; Vianna et al 2017 ). The leaf blade has provided useful characters to discriminate between species in some genera of the family, such as Oenocarpus ( Silva and Potiguara 2008 ; Tomnlinson et al 2011 ), Syagrus ( Glassman 1970 ; Tomnlinson et al 2011 ; Noblick 2013 ; Noblick et al 2014 ), Allagoptera ( Tomnlinson et al 2011 ; Martins et al 2015 ; Pinedo et al 2016 ), Parajubaea ( Meerow et al 2009 ; Tomnlinson et al 2011 ), Acrocomia ( Vianna et al 2017 ) and even Butia ( Noblick 2014 ; Sant’Anna-Santos et al 2015 ). A detailed comparative study of the leaf anatomy of Butia provided useful characters that corroborated the split of B. odorata from B. capitata and aid in their distinction ( Sant’Anna-Santos et al 2015 ).…”