Capsicum carassense (Solanaceae), a new species from the Brazilian Atlantic Forest

Abstract Capsicum carassense Barboza & Bianchetti sp. nov., a species from mid-elevation of the Atlantic Forest (Minas Gerais, Brazil) is described and illustrated. This endemic new species is distinguished from the most similar C. mirabile Mart. by its moderate to dense general pubescence, narrowly elliptic leaves and larger calyx appendages and corollas. A key for the native Brazilian species of Capsicum growing in the state of Minas Gerais is also provided.

logical properties (Papoiu and Yosipovitch 2010, Al-Snafi 2015, Parvez 2017) and several constitute major vegetable and spice crops worldwide (Jarret et al. 2019), mainly due to the presence of compounds unique to Capsicum, the capsaicinoids, which are responsible for the pungency of the fruits. The genus is native to tropical and temperate Central and South America, Mexico and the West Indies , with five species widely cultivated throughout Europe, the southern United States, Africa, India, China and South America (Pickersgill 1997, Basu and De 2003, Libreros et al. 2014, Scaldaferro et al. 2018. There are two main centres of diversity for Capsicum, the Andes and Brazil (Barboza et al. in prep.). For both centres, new species have been described in recent years (Barboza andBianchetti 2005, Nee et al. 2006, Barboza 2011. Brazil is an extensive country that hosts the most diverse flora within the Americas (Ulloa Ulloa et al. 2017, BFG 2018 and Capsicum has 50% of its species growing in its territory. Additionally, Brazil's Atlantic Forest is the fourth leading hotspot in terms of endemic plants (2.7% of global total, Myers et al. 2000), where ten Capsicum species are endemic , some with very restricted distributions (e.g. C. friburgense Bianchetti & Barboza and C. hunzikerianum Barboza & Bianchetti).
While working with the genus on the Flora do Brasil 2020 project, we revised several Brazilian herbaria and visited the Serra do Caraça, a historical natural reserve with remnants of semi-deciduous montane forest in the Iron Quadrangle, in Minas Gerais state. There, we found some populations that were recognised at first glance as belonging to C. mirabile Mart., a species that typically occurs in montane rainforests in south-eastern Brazil. Capsicum species from different regions of the Atlantic forest were included in the broad molecular phylogeny of the genus, based on nuclear and chloroplast markers (Carrizo . The new species, denoted as Capsicum aff. mirabile in Carrizo  was not sister to the C. mirabile accession included in these analyses, suggesting that it may be an undescribed taxon. Then, we reviewed in detail the morphology of the Capsicum species of the Brazilian interior and coastal forests and determined that the populations from Serra do Caraça and surroundings represent a distinct species of C. mirabile. Here, we describe and illustrate this new species and provide comments on taxonomy, ecology and conservation, taking into account its occurrence in a region heavily threatened by mining activities.

Material and methods
The description is based on observations and data taken from specimens collected in the field between 1986 to 2019, mainly in Serra do Caraça (Minas Gerais, Brazil) and examination of herbarium specimens from 13 herbaria (BHCB, BHZB, BM, CEN, CORD, ESA, JPB, M, MBM, RB, SP, UEC and UT). Specimens have been accessed in situ or through digital images via INCT Herbário Virtual (http://inct.splink.org.br), Herbário Virtual Reflora (http://reflora.jbrj.gov.br/reflora/herbarioVirtual) or Global Plants (https://plants.jstor.org/) databases. Measurements were made from preserved material in FAA solution (formaldehyde -acetic acid -ethanol) or from living material using a Zeiss Stemi 2000-C stereomicroscope at 6.5-50× magnification. Information on corolla and fruit colour and pungency of fruit was recorded from living material in the fieldwork. Illustrations were made by composite line drawings from preserved material. Photographs were taken during fieldwork by the authors; images were edited using Adobe PhotoshopVR.
To compare this new species with its morphologically similar congener (C. mirabile), about 200 specimens of C. mirabile were analysed (see Suppl. material 1), using the same methods (fieldwork and examination of living and herbarium collections). To assess C. carassense and C. mirabile distributions in Minas Gerais, latitude and longitude data indicated on the labels were directly mapped; other localities were georeferenced by searching the locality by GeoLoc tools (https://splink.cria.org.br/ geoloc). QuantumGis (QGIS V. 2.18) was used to build the distribution map. Conservation status was assessed using primarily the IUCN criteria B, geographic range in the form of B1 (extent of occurrence, EOO) and B2 (area of occupancy, AOO) (IUCN 2019). The EOO and AOO were calculated using the Geospatial Conservation Assessment Tool, GeoCAT (Bachman et al. 2011) and AOO was based on a defined cell width of 2 km.
Ecology. The population studied in the field at Serra do Caraça inhabits the understorey of the semi-deciduous montane Atlantic Forest, in a shaded and moist environment. Information about pollination and dispersal is not yet known.
Phenology. In flower from October to January, also in May; fruiting in December, February and April.
Etymology. The new species is named in allusion to its restricted habitat in the Serra of Caraça and surrounding areas (Minas Gerais, Brazil).
Preliminary assessment of conservation status. Following the IUCN Red List Criteria (IUCN 2019), this species is considered Endangered (EN) B2 a,b (iii, iv). We suggest this category, because of the species' very restricted geographic distribution (EOO < 483.4 km 2 , AOO < 32 km 2 ), as well as the increasingly degraded habitat quality, especially associated with the extensive iron mining activities in the region (see below). Discussion. Capsicum carassense belongs to the Atlantic Forest clade (sensu Carrizo García et al. 2016, as Capsicum aff. mirabile). For many years, this species has long been confused with C. mirabile in herbaria (Bianchetti 1996, Barboza per. obs.). Both species share similar traits, such as habit, geniculate pedicels at anthesis, number of calyx appendages, the shape and colour of the corolla, colour and pungency of the fruits and blackish seeds. They can be easily distinguished by the indumentum, shape of the major leaf and its length/width ratio, length of the calyx appendages, corolla size and ecology and distribution (see Table 1 for contrasting details).
Capsicum carassense is a pubescent low shrub with very narrow leaves and large white corollas with purple-spots. The shape and length/width ratio of the leaves of C. carassense are very close to the description of C. mirabile var. grandiflorum Sendtn. (Sendtner 1846) but Sendtner also stated that this variety had "floribus majoribus" and "planta glaberrima". The diameter of the corolla measured in three flowers in the F neg. 2871 of the destroyed varietal holotype (Sellow 209, Herb. Reg. Berolinense) is not more than 1 cm (https://collections-botany.fieldmuseum.org/project/6454), thus these two traits, size of the corolla and lack of pubescence fit with the concept of C. mirabile rather than C. carassense.
Capsicum carassense and C. mirabile differ in geographic distribution, with the former inhabiting mostly the understorey of the semi-deciduous montane forests of the southernmost areas of the Espinhaço Range in Minas Gerais, while the latter has a wider distribution (Barboza and Bianchetti 2005), growing mostly along the dense ombrophilous montane forest of south-eastern Brazil, an area characterised by high rainfall and humidity and the absence of a pronounced dry season (Silva Magnago et al. 2007). Both species have a contact zone at the municipalities of Mariana and Ouro Preto, in the Serra do Itacolomi, where C. carassense, as well as two other species, C. mirabile and C. villosum Sendtn., were recorded. There is no information about edaphic preferences for these species, nor possible events of hybridisation in this contact area.
All collections of the new species come from the Iron Quadrangle in Minas Gerais, except one historical Martius specimen at M [M!, photo n° 6522 at F!], collected in the Serra de São Geraldo between Mariana and Presídio de São João Batista (today the municipality of Visconde do Rio Branco). This material, a syntype of C. mirabile (Sendtner 1846), was examined when Barboza (2011) lectotypified C. mirabile. She stated that "the third syntype […] is unusually pubescent for this species". Here, we re-examined this specimen housed at M (M-0171537) and concluded that it actually belongs to C. carassense.
The relationships amongst the species belonging to the Atlantic Forest clade appear to be fully resolved and an apparent phase of rapid speciation has been suggested for this lineage (Carrizo . In spite of the morphological similarity between C. carassense and C. mirabile, these species are not closely related phylogenetically, as C. carassense (as Capsicum aff. mirabile in Carrizo  is not sister to C. mirabile, but occurs in a different subclade of the Atlantic Forest clade. In the analysis of Carrizo , C. mirabile appears closest to C. villosum var. muticum Sendtn. The new species deserves conservation attention, because few populations are known and most of them are distributed in the Iron Quadrangle and associated with remnants of native forests. This area was assessed as priority for conservation in the state of Minas Gerais (Drummond et al. 2005), with high animal and plant diversity and extensive threats, especially from iron mining activities (Jacobi et al. 2011, Salles et al. 2018. The impacts on native vegetation, especially forests, are high because of the activities associated with iron and bauxite mining as the building of dams and urban expansion, all increase deforestation pressures at regional-scale (Sonter et al. 2014).
Artificial key to the 11 native Brazilian species growing in the state of Minas Gerais (excluding cultivated species)