Leaf anatomy of six species of Heliotropiaceae Schrad. from the Brazilian semi-arid region

Elisabeth Tölke,José Iranildo Miranda De Melo,Sandra Maria Carmello-Guerreiro

doi:10.5007/2175-7925.2015v28n3p1

Elisabeth Tölke, José Iranildo Miranda De Melo + Show 1 more

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https://doi.org/10.5007/2175-7925.2015v28n3p1

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Abstract

The family Heliotropiaceae has more than 450 species, mainly distributed in the tropics and subtropics. In Brazil, it is represented by the genera Euploca Nutt., Heliotropium L., Myriopus Small and Tournefortia L. The aim of this study was to describe the leaf anatomy of six species of Heliotropiaceae recorded in the semi-arid region of Brazil: E. polyphylla (Lehm.) J.I.M. Melo & Semir, E. procumbens (Mill.) Diane & Hilger, H. angiospermum Murray, H. curassavicum L., M. rubicundus (Salzm. ex DC.) Luebert and M. salzmannii (DC.) Diane & Hilger. Besides contributing to the knowledge of the anatomy of the representatives of the family in the Caatinga (Brazilian savannah), we also sought to determine and highlight the anatomical features adaptive to the region and to identify features with potential diagnostic value. Leaf structures were analyzed by light microscopy and scanning electron microscopy. Additional tests were also carried out to detect starch and total lipids. The morphological variation and the distribution of trichomes were the most relevant features for species diagnosis. The distribution of stomata in M. salzmannii and H. angiospermum differed from that described in other papers, which demonstrates the anatomical plasticity of these species. This is the first report describing the leaf blade of M. rubicundus .

Highlights

The family Heliotropiaceae is mainly distributed in the tropics and subtropics and comprises ive genera and approximately 450 species (DIANE et al, 2002; 2003; GOTTSCHLING et al, 2004; LUEBERT et al, 2011)
In Brazil, it is represented by the four genera Euploca Nutt., Heliotropium L., Tournefortia L. and Myriopus Small (MELO et al, 2009)
This study aimed to describe the leaf anatomy of six species of Heliotropiaceae found in the Brazilian semi-arid region, Caatinga biome: Euploca polyphylla, E. procumbens, Heliotropium angiospermum, H. curassavicum, Myriopus rubicundus and M. salzmannii

Summary

Introduction

The family Heliotropiaceae is mainly distributed in the tropics and subtropics and comprises ive genera and approximately 450 species (DIANE et al, 2002; 2003; GOTTSCHLING et al, 2004; LUEBERT et al, 2011). In Brazil, it is represented by the four genera Euploca Nutt., Heliotropium L., Tournefortia L. and Myriopus Small (MELO et al, 2009). Its representatives are allocated into two sections: Tournefortia sect. Tournefortia I.M. Johnst., with straight embryo and slightly lobed fruits; and T. sect. Cyphocyema I.M. Johnst., with curved embryo and a four-lobed fruit (CAVALHEIRO et al, 2011). In Brazil, both sections are represented by approximately 25 species (MELO et al, 2009). Cyphocyema in the genus Myriopus has been suggested by phylogenetic studies combined with morphological data, showing T. sect. The species chosen for this study are in the genus Myriopus

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