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

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.

A new record for Guyana reveals the disjunct distribution of Tragia cearensis Pax & K. Hoffm. (Euphorbiaceae) 

“…This combination of characters is slightly different from what was found in Guyana specimens by Gillespie and Armbruster (1997), as they did not find glandular trichomes in their study. At any rate, the collection that we report in this article is compatible with the morphological concept of T. cearensis, based on flowers and fruits with short pedicels (1-1.2 mm long) and ovary without capitate glandular trichomes (Santos et al 2019). Seeds with large papillae, such as those found on T. cearensis (50-100 μm), are not frequent in South American species (Múlgura de Romero and Gutiérrez de Sanguinetti 1989).…”

“…The Guyana collection (Jansen-Jacobs et al 4017) was labeled as Tragia volubilis, but did not have any of the diagnostic characteristics: glandular trichomes (short, pedicellate or capitate), pistillate flowers with long pedicels, and seeds light brown with a papillose coat (Múlgura de Romero and Gutiérrez de Sanguinetti 1989; Santos et al 2019). This combination of characters is slightly different from what was found in Guyana specimens by Gillespie and Armbruster (1997), as they did not find glandular trichomes in their study.…”

“…Due to our incomplete knowledge, T. cearensis was previously considered endemic to Caatinga areas in Ceará state, Brazil (BFG 2015(BFG , 2018Govaerts et al 2020). Recently, Santos et al (2019) expanded it as endemic to the Caatinga domain in the states of Alagoas, Paraíba, Rio Grande do Norte, and Sergipe. Here, we report the first occurrence of that species in Guyana in an area of savanna vegetation at 120 m a.s.l.…”

“…Tragia cearensis was described by Pax and Hoffman (1924) based on a specimen collected in Ceará state in northeastern Brazil. Santos et al (2019) recently expanded the distribution of that species by recognizing new records in neighboring states. Morphologically, the species can be distinguished by the absence of capitate glandular trichomes on reproductive structures and the verruculose coat of its seeds (Santos et al 2019).…”

Climbing plants from Seridó Ecological Station: diversity, interactive key and five new records from Rio Grande do Norte state, Brazil

“…Five new occurrences were found for the state of Rio Grande do Norte (Tab. (Santos et al 2019). Some listed species have economic, medicinal and ornamental importance: Cucumis anguria, popularly known as maxixe, is widely consumed and cultivated in the region; Momodica charantia and Luffa operculata have several uses in traditional medicine (Silva & Freire 2010) as in the pharmaceutical industry (Champney et al 1978); and Alamanda blanchetti (Fig.…”