New record of Vitex orinocensis Kunth (Lamiaceae) for the state of Ceará, Brazil: insights on its conservation

. We report the first record of Vitex orinocensis Kunth (Lamiaceae) from Ceará state, northeastern Brazil. This species was collected in an upland Semideciduous Seasonal Forest. This occurrence adds new information about the flora of Ceará and expands the geographic range of this species in Brazil, which is important for its conservation. We provide taxonomic information, distribution map, implications for its conservation status, photographs, and a identification key for the Vitex Tour. ex L. species from Ceará.


Introduction
The Brazilian Atlantic Forest domain is one of the 25 global priorities for biodiversity conservation and harbors about 20,000 species of vascular plants, of which 8,000 are endemic (Tabarelli and Santos 2004). Tabarelli and Santos (2004) claimed that the biodiversity of this phytogeographic domain is distributed in five centers of endemism and that one of these centers comprises upland forests, which are "islands" of Semideciduous Seasonal Forest located in the states of Ceará and Piauí, in the Caatinga domain. The origin of these islands is associated with the occurrence of plateaus and layers between elevations of 500 and 1,000 m, which provide orographic rains that guarantee climatic conditions that favor the survival of several groups of plants typical of the Atlantic Forest in the semiarid region (Tabarelli and Santos 2004;Cardoso 2011).
Vitex Tour. ex L. (Lamiaceae) stands out with 250 species distributed throughout tropical and subtropical regions (Bramley et al. 2009). In Brazil, there are 34 species (23 spp. endemic) distributed in all geopolitical regions and in the Amazon, Caatinga, Cerrado, Atlantic Forest, and Pantanal domains (Flora do Brasil 2020). Among these, the Atlantic Forest and Cerrado stand out in having the second greatest species diversity for this genus (13 spp. each) (Flora do Brasil 2020). Vitex is charaterized by arboreal or shrub habits, rarely prostrate; leaves are compound-palmate to trifoliolate (or unifoliolate in some cases); inflorescence is terminal or axillary, the calyx is campanulate or cupuliform, the corolla is (4-)5-lobed, infundibuliform; anthers are black to purple; and the fruit drupe globose, with 1-4 seeds (Bramley et al. 2009).
During a floristic survey in areas of Semideciduous Seasonal Forest in the Serra de Itacoatiara, Ceará state, V. orinocensis Kunth was identified and recorded for the first time from the state. It had been recorded in the Northeast Region of Brazil from the states of Bahia, Maranhão, Paraíba, and Pernambuco, covering areas of both Amazon and Atlantic Forests (Monteiro et al. 2018;Flora do Brasil 2020).
Considering the importance of recording the real distribution of species in order to assess the ecological and morphological range, distribution pattern, and to evaluate conservation status, we report the first record of V. orinocensis from Ceará. Herein, we present a morphological description, identification key to Vitex species in Ceará, photographs, comments on the geographic distribution, and information for a future assessment of its conservation status.

Methods
Serra de Itacoatiara is located in Maciço da Uruburetama (03°34′34″S, 039°36′00″W; 700-1,000 m a.s.l.), northern Ceará, Brazil (Fig. 1). Serra de Itacoatiara is located in the municipality of Itapipoca and is comprised of Semideciduous Seasonal Forest in an upland forest. It has a Tropical Hot Semi-arid climate and rainfall of 1,130.4 mm per year, and an average temperature of 26 °C (Bezerra et al. 1989). The floristic survery was carried out between 2013 and 2016, during which some species of Vitex were collected and processed according to the usual taxonomic techniques (Mori et al. 1989) and deposited in the Herbarium Prof. Francisco José de Abreu Matos, Universidade Estadual Vale do Acaraú, Sobral (HUVA), and Herbarium Prisco Bezerra, Universidade Federal do Ceará, Fortaleza (EAC) (acronyms according to Thiers 2019). The identification was determined through morphological comparison with exsiccates that were previously identified by experts and available on the speciesLink database (http://www.splink.org.br/); the identification was confirmed by the study of type collections available online (https://plants.jstor.org/). The morphological description was based on the samples collected and uses the terminology adopted by Harris and Harris (2001). Data referring to the flowering and fruiting period was obtained from field observations. The distribution map was prepared with QGIS v. 1.4 (QGIS 2016) using records with original geographical coordinates and those that were taxonomically verified by an expert. These records were obtained from the speciesLink. The main diagnostic characters have been illustrated.

Results
Identification key to species of Vitex in Ceará state   ( Fig. 4). This species was seen flowering and fruiting in March.

Conservation status.
Vitex orinocensis is an unevaluated species (NE) (Flora do Brasil 2020), and in Ceará state it is not known to occur in any protected area. In its area of occurence, the threats to the small population of V. orinocensis are mainly associated with habitat loss due to agricultural activities, such as banana monocultures; this emphasizes the importance of creating new conservation units in Atlantic Forest areas of the state. Our new record expands the occurrence of V. orinocensis to the north of the Northeast Region, and is important for future assessment of the conservation status of this species.

Discussion
According to Flora do Brasil (2020) and considering the vegetation classification of Ceará state (Moro et al. 2015), seven species of Vitex are widely distributed in different vegetation types in the state. The rocky-outcrop habitat where we report Vitex orinocensiswas also mentioned by Monteiro et al. (2018) for Paraíba state, confirming that this species grows on rocky outcrop in the Atlantic Forest. Considering its disjunct distribution between the Amazon and Atlantic Forests, the occurrence of V. orinocensis in upland forest may be suport the hypothesis that these ecosystems constitute refuges for Atlantic Forest species, whose ancestors were continuously distributed between these two domains during the Pleistocene glacial periods (Tabarelli and Santos 2004; Batalha-Filho and Miyaki 2014). As for conservation, it is important to mention that our new record of V. orinocensis expands not only the area of occurrence of this species but also its geographic range. This information will be important for future assessments of the conservation status of this species following the B1 criterion of the International Union for Conservation of Nature Red List. New records that are taxonomically verified are essential for assessing the conservation status of species (Marinho and Beech 2020). Our new record reinforces the need to expand floristic studies in Ceará state in order to increase knowledge of the distribution of V. orinocensis and reduce gaps in its geographic distribution. This record also shows the importance of creating of new conservation units in the upland forests of the state.
Federal Rural de Pernambuco for financial support of our research; to Regina Carvalho for the illustrations; and Hannah Doerrier for the English review.