Gymnanthes boticario, Esser, M. F. Lucena & M. Alves, 2010

De Oliveira, Luciana Dos Santos D., Moro, Marcelo Freire, Nic Lughadha, Eimear M., Martins, Fernando Roberto, Melo, André Laurênio De, Esser, Hans-Joachim & Sales, Margareth F., 2013, Hidden in the dry woods: Mapping the collection history and distribution of Gymnanthes boticario, a well-collected but very recently described species restricted to the dry vegetation of South America, Phytotaxa 97 (1), pp. 1-16 : 2

Gymnanthes boticario in Caatinga and beyond

Historically, the semiarid Caatinga was one of the most scientifically overlooked areas of Brazil. Assumed to be poor in species diversity and endemism, few efforts to study its flora and establish nature reserves were made up to the 1990s, and even now less than 2% of its area is protected by Nature Reserves ( Tabarelli & Vicente 2002, Castelletti et al. 2003). Studies in Caatinga intensified sharply in the last decade and now show that the Caatinga is a semiarid area rich in plant diversity and with many endemic genera and species [e.g. the monotypic genera Holoregmia Nees von Esenbeck (1821: 300) ( Harley et al. 2003) and various species of Fabaceae ( Queiroz 2009) , Cactaceae ( Taylor & Zappi 2004) and Euphorbiaceae ( Lucena & Alves 2010) ]. In 2002 a first synthesis of the plant biodiversity in the Caatinga was prepared ( Sampaio et al. 2002), and in 2006 a general catalogue of the plant species was published ( Giulietti et al. 2006), recognizing 5344 species in the Brazilian semiarid region and 1511 species in the Caatinga sensu stricto vegetation. A new list of species was published in 2010 as part of the List of Plants of Brazil, recording 4320 Angiosperms for the semiarid region of Brazil (Caatinga Phytogeographical Domain, or Caatinga sensu lato) ( Forzza et al. 2010). Several new species have been published since this recent comprehensive list, including the subject of this paper, G. boticario .

Gymnanthes boticario Esser, M.F.Lucena & M.Alves (2010: 345) is a Euphorbiaceae species, of the Hippomaneae tribe, recently described from the Caatinga vegetation in Northeastern Brazil ( Esser et al. 2010). The plant is easily recognized in the genus by the presence of indumentum, usually serrate (rarely entire) margins of the leaves, the short petiole, densely tomentose ovary and subsessile fruits. In the protologue, 14 collections from Bahia, Ceará, Pernambuco, Piauí and Rio Grande do Norte states are cited, indicating that the plant has a wide distributional range. During a general revision of Gymnanthes Swartz (1788: 6) by the first author, dozens of other specimens of this plant were recorded in many herbaria, demonstrating a surprising amount of unpublished distributional data available about such a newly recognized plant, and stimulating us to map the occurrences of it. A study visit to G, K and M herbaria revealed new records for Mato Grosso do Sul state, Brazil, Bolivia and Paraguay, indicating that this new species is not only well collected, but also quite widely distributed in South America, with a pattern that matches closely the Pleistocenic Arc proposed by Prado & Gibbs (1993). Our purposes are thus 1) to record the history of collections made of G. boticario up to its description, exploring the factors that may cause a widely collected plant to remain unrecognized a long time before description; 2) to map the known distribution of the plant, revealing its ecological preferences; 3) to report the first records for G. boticario for the dry forests of Pantanal ecoregion in Mato Grosso do Sul, Brazil; for Paraguay, in Cerro Léon dry forests; and also for Bolivia, in Chiquitano dry forests, also contributing to the Catalogue of Vascular Plants of Bolivia, now in preparation; and 4) to discuss the implications of this new disjunct record for the hypothesis of the Pleistocenic Arc.