Taxonomic relevance of leaf anatomy in Banisteriopsis C.B. Rob. (Malpighiaceae)

Abstract

We describe the leaf anatomy of 42 of the 60 species of the genus Banisteriopsis, one of the largest and most diverse genera of Malpighiaceae in the Cerrado domain. Our aim was to identify anatomical leaf characters useful for the taxonomy and systematics of this morphological diverse genus. Expanded leaves from herbarium specimens were rehydrated and processed according to usual anatomical methods for analysis under light microscopy. All characters were compared using the Unweighted Pair Group Method with Arithmetic Mean algorithm and expressed in dendrograms. The most useful leaf anatomical characters were petiole contour, presence/absence of vascular bundles in the petiole, the position of the vascular bundles in the petiole, shape of the midrib, presence/absence of sheath extension, mesophyll type, and both the presence/absence and shape of leaf glands. Our study indicates that the morphological groups proposed in the literature for Banisteriopsis are natural groups.

The taxonomic value of leaf anatomy for species Byrsonima: a difficult genus of Malpighiaceae Juss.

“…Our findings are congruent with a recent anatomical study in Banisteriopsis, whose authors showed the taxonomic relevance of anatomical characters to support the monophyletism of informal groups, being promising in a new infrageneric classification (Araújo et al 2020). In addition, characters such as biconvex contour of petioles with two protuberances, bistratified non-continuous epidermis on both surfaces of the leaf blade, paracytic laterocytic stomata, and medullary phloem in the petioles were reported here for the first time in Byrsonima and should be highlighted in future anatomical studies in Malpighiaceae.…”

“…The anatomy of petioles shows little influence of environmental pressure and might represent great taxonomic value in different taxa (Metcalfe & Chalk 1957). The four types of petiole contour found in our study corroborates the results presented by Silva et al (2011), and studies on different genera, such as Stigmaphyllon (Guimarães et al 2016), and Banisteriopsis (Araújo et al 2020). The variation evidenced in this feature makes it a useful tool in the circumscription of species and genera in Malpighiaceae, especially in Byrsonima, the second largest and most taxonomic challenging genus in the family according to Almeida et al (2016).…”

“…The presence of medullary phloem in the midrib is another distinctive character for Byrsonima and it has been used to differentiate genera and species in Malpighiaceae (Araújo et al 2010;Silva 2014). The vascular system conformation in the midrib has also been regarded as an important feature by several authors due to the variation or constancy within species, representing a great phylogenetic signal in the genus (Araújo et al 2010;Almeida et al 2019;Mello et al 2019;Araújo et al 2020).…”

“…It provides additional informative features which helps to understand its morphological evolution (Metcalfe & Chalk 1979;Endress et al 2000). Leaf anatomy is widely used as an aid in flowering plants taxonomy, especially in groups with taxonomic problems, as in Malpighiaceae (Metcalfe & Chalk 1957;Gomes et al 2009;Araújo et al 2010;Almeida-Jr et al 2013;Almeida et al 2017;Guesdon et al 2018;Almeida et al 2019;Araújo et al 2020). Even though leaf anatomy of Byrsonima species has been explored in previous studies, few have listed features that can be attributed to a new classification system for the genus (Araújo et al 2010;Silva 2014).…”

New records of Bronwenia megaptera (B. Gates) W. R. Anderson & C. C. Davis for the State of Piauí, Brazil

“…Several authors have used anatomy to help differentiate Malpighiaceae species such as Araújo et al (2010) who analyzed some species of the genera Banisteriopsis, Byrsonima and Heteropterys. Araújo et al (2020) in their work they used the technique to characterize and distinguish Banisteriopsis species occurring in Brazil. Other works are noteworthy, such as Mamede (1993), which characterized Camarea species; Guimarões et al (2016) performed the anatomical description of three species of Stigmaphyllon, Guesdon et al (2018) with the characterization of the genus Glandonia and Almeida et al (2017) studied Amorimia species.…”