The genera Bernardia Houst. ex Mill. and Tragia L. (Euphorbiaceae, Acalyphoideae) in Northeastern Brazil

Mirane De Oliveira Santos,Margareth Ferreira De Sales,Wesley Patrício Freire De Sá Cordeiro,Juliana Santos Silva

doi:10.1590/1676-0611-bn-2018-0592

Mirane De Oliveira Santos, Margareth Ferreira De Sales + Show 2 more

Open Access

https://doi.org/10.1590/1676-0611-bn-2018-0592

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Abstract

Abstract: Bernardia and Tragia are genera of the subfamily Acalyphoideae, with species occurring in tropical and subtropical regions. Studies concerning those genera are scarce in Brazil, including Northeastern Brazil. The present study was designed to study the taxonomy of species occurring there, and provides illustrations, keys, descriptions, and comments concerning taxonomic affinities, as well as information concerning their geographic distributions and environmental preferences. A total of 13 species were encountered, eight of Bernardia and five of Tragia. Of those, B. hamadryadica and T. cearensis are endemic to Northeastern Brazil and B. celastrinea, B. pulchella, and T. chlorocaulon are new records for the region. The two genera occur in moist Atlantic forests, in forest borders, and anthropically impacted areas. New occurrences were recorded in all of the states, totaling 21 new records. The principal diagnostic characters for distinguish were: the sexuality of the plant (monoecious or dioecious), the presence of foliar glands, the types of inflorescence and trichomes, and the numbers of stamens. Among the 13 species encountered, six are illustrated here for the first time.

Highlights

The family Euphorbiaceae is one of the most diverse families of Malpighiales, with 6,300 species and 219 genera, occurring predominantly in tropical and subtropical regions (APG IV 2016, Wurdack et al 2005, Wurdack & Davis 2009)
We examined approximately 1,000 specimens of Bernardia and Tragia deposited in the principal herbaria in the northeastern region (ALCB, CEPEC, EAC, HRB, HUEFS, HUNEB, IAN, IPA, JPB, PEUFR, UFP, and HESBRA and HST of Federal Rural of Pernambuco), as well as in a herbarium in southeastern Brazil (RB); acronyms according to Thiers 2018
Thirteen species were recorded in the study area, eight of Bernardia and five of Tragia, representing 35% of the Brazilian species of Bernardia and 31% of Tragia

Summary

Introduction

The family Euphorbiaceae is one of the most diverse families of Malpighiales, with 6,300 species and 219 genera, occurring predominantly in tropical and subtropical regions (APG IV 2016, Wurdack et al 2005, Wurdack & Davis 2009). Acalyphoideae is the largest and most complex subfamily of Euphorbiaceae, comprising 99 genera and 3,000 species (Webster 2014). Seven species occur in Northeastern Brazil [Bernardia axillaris (Spreng.) Müll. The genus is represented by five species in Northeastern Brazil In spite of the great richness and morphological diversity of the species of Euphorbiaceae in Brazil, studies of the genera Bernardia and Tragia have been very rare there. The present work examined the taxonomy of the species of Bernardia and Tragia occurring in Northeastern Brazil to contribute to a better understanding of those genera, provide keys, morphological descriptions, illustrations, and data concerning their geographic distributions and preferred habitats, to amplify our knowledge of that region’s vegetation and to serve as a basis for future taxonomic revisions

Study area

Taxonomic study

Results and Discussion