New insights from Solanum fernandesii (Solanaceae)

, field images, comments, and identification key for species of the genus Solanum in the study area are presented.


Introduction
Solanaceae is an important botanical family with a wide range morphological diversity, habits and habitats.It is one of the most economically important angiosperm families, used for a variety purposes including food (e.g., Solanum lycopersicum L., tomate; S. tuberosum L., batata; S. melongena L., beringela), medicinal or source of medicinal compounds (e.g., Nicotiana tabacum L. and N. rustica L., fumo or tabaco; Atropa belladonna L., beladona), ornamental (e.g., Petunia hybrida Hort., petúnia; Salpiglossis sinuata Ruiz & Pav., flor-de-trombeta, see Knapp et al., 2004), among others, ensuring an essential role in the sustainability of local communities around the world (Poczai et al., 2022).In this way, species of this family are used as important and different human adaptation strategies, especially to deal with illness events (Kutal et al., 2021;Hankiso et al., 2023;Liu et al. 2023).
Solanaceae comprises 99 genera and approximately 2.700 species (Poczai et al., 2022), with a cosmopolitan distribution, concentrating the highest rates of diversity and endemism for the family in the Neotropics (Hunziker, 2001;Olmstead, 2013).South America is its center of origin and diversification, with subsequent dispersion to other parts of the world (Olmstead, 2013).
In Brazil, there are 506 species distributed in 36 genera, with 236 species and four endemic genera (Solanaceae in Flora e Funga do Brasil, 2023).Among the genera that constitute the family, Solanum stands out for its great diversity in number of species, high morphological variation, and great economic importance (Knapp, 2008).There are 291 species for the genus in Brazil, with 143 of them being endemic, found in the most diverse types of vegetation, mainly in the Atlantic Forest (Solanaceae in Flora e Funga do Brasil, 2023).
Among the species of this genus, there is Solanum fernandesii V.S. Sampaio & R. Moura.It species is native and endemic to Brazilian territory, and has been recently published for science, and belongs to the Gardneri clade (Sampaio et al., 2016), which is still constituted by some species, which include S. agrarium Sendtn., S. gardneri Sendtn., S. polytrichum Moric, S. schomburghii Sendtn., and S. stenandrum Sendtn.(Stern et al., 2011).Members of this clade are species native to Brazil, the Caribbean, and one species from northern Peru.The delimitation of this clade is complex.However, the possible characteristics that unite these species are the slender stem, herbaceous to shrubby habit, straight spines, commonly acicular, small leaves in many species; inflorescences simple, lateral pauciflorous; accrescent fruit calyxes, and a preference for arid environments (Silva, 2014).
Solanum fernandesii is characterized by having resin glands on the petiole, the first record for the genus, and uncommon, which secrete a mixture containing phenolic compounds, polysaccharides, pectins, mucilage, proteins, lipids, oils, and resins (Sampaio et al., 2021).
The first collection of the species was carried out in 1954, by Andrade-Lima, in the locality of Barreiras, municipality of Petrolândia, Pernambuco, Northeastern Brazil.Due to being like other species, it was often confused with S. flagellare Sendtn., S. stenandrum, and, mainly, S. agrarium (SpeciesLink, 2023).Only in 2016, Sampaio and collaborators recognized it as a new species, presenting a set of characteristics that define S. fernandesii as a unique species (see Sampaio et al., 2016), and that separated it from the others hitherto confused, occurring in the states of Ceará, Pernambuco, Bahia, Alagoas and Minas Gerais (SpeciesLink, 2023).Since then, the knowledge about the species has advanced with morphological and anatomical studies (Sampaio et al., 2019(Sampaio et al., , 2021)).
Despite advances in knowledge about the species, we need to advance in many aspects involving its biology, especially in its current geographic distribution and conservation status.In this way, according to Poczai et al. (2022), the decrease in the resilience of ecosystems that suffer biodiversity loss increased the urgency of promoting the conservation and sustainable use of species of this family.
Considering what has been reported, we seek to answer the following questions: What characteristics allow the identification of S. fernandesii?In what diversity of habitats or landscapes does it occur?What is its geographic distribution in Brazil?What is your conservation status?By answering these questions, we hope to contribute to the knowledge of S. fernandesii, an important and unusual species of the genus Solanum.
Therefore, based on the status of knowledge regarding the species, in the present study, we report for the first time the occurrence of S. fernandesii for the Piauí state, Northeastern Brazil, thus expanding its geographic distribution area, in addition to providing general comments and information about its conservation status and the different types of landscapes in which it occurs.In addition, field images of S. fernandesii and an identification key of Solanum species for the municipality of Cocal/PI are presented.

Study area
In Piauí state, S. fernandesii was collected in the Franco rural community (3º29'49.7"Sand 41º26'17.0"W),municipality of Cocal, north of Piauí (Fig. 1).The municipality is 268 km from the state capital, Teresina.The collection site of the species is within the limits of the Environmental Protection Area (EPA) of Serra da Ibiapaba (Brasil, 1996).The area of the municipality is located under the Aw' -Tropical climate domains, with two well-marked seasons: rainy summer and hot winter, with temperatures ranging between 25 and 35 ºC.The average annual rainfall is 900 mm (Medeiros, 2004).The vegetation is described as Carrasco.This type of deciduous vegetation is characterized by the predominance of woody, shrubby, branched plants and by the strong presence of vines, with great emphasis on species of the Asteraceae, Bignoniaceae, Euphorbiaceae, Fabaceae, Malpighiaceae, and Rubiaceae botanical families (Chaves, 2005).Vegetation transitions such as hyperxerophilous Caatinga and Cerrado also occur in the study area (Jacomine, 1986).Figure 2 shows some landscapes in the Cocal municipality.

Collection and identification of botanical material
Solanum fernandesii was collected according to usual techniques for the collection and herborization of botanical materials (Mori et al., 1989), between February and March 2020, in the Franco rural community, during the conduct of an ethnobotanical investigation by the first author.The material was identified using a dichotomous key for the genus Solanum occurring in Ceará state (Sampaio et al., 2019)  The morphological description and terminology followed the delineations proposed by Radford (1974), Agra et al. (2009), Gonçalvez e Lorenzi (2011), and Sampaio et al. (2016Sampaio et al. ( , 2019)).The confirmation of the names of the taxa presented here was consulted in the International Plant Names Index -IPNI (2023).

Geographic distribution and conservation status
To obtain data on the occurrence of the species in Brazil, the resources of the online tools SpeciesLink (https://specieslink.net/search/) and the Reflora Virtual Herbarium (reflora.jbrj.gov.br) were used.In this sense, we organized a spreadsheet in Excel® with data on the genus of the species, scientific epithet, state of collection, municipality, and information on latitude and longitude.Data from scanned labels and exsiccates (when available) was carefully reviewed so that the selected material was correctly identified.
For records with general or imprecise geographic coordinates, searches were carried out in the Google Earth tool (https://earth.google.com/web/)using the information on the herbarium labels to more accurately locate the areas of occurrence of the species.For records collected in the same area or at geographically close points, it was decided to select only the coordinates of one of them as an instrument for analyzing the geographic distribution of the species.
During the study of sorting the occurrence points, 30 records were reported in SpeciesLink, while 11 were located in the Reflora Virtual Herbarium, the latter being duplicated and previously sorted in SpeciesLink, in addition to three occurrence records for the municipality of Cocal (PI) from fieldwork and botanical excursions that were added to the list, totaling 33 records.Excluding duplicate points or very close populations, 17 records were selected for the delimitation of the Extent of Occurrence and Area of Occupation of the species, according to subsequent descriptions.
From the geographic coordinates data, the points were plotted on maps of geographic distribution running the software QGIS version 3.22 (https://www.qgis.org/es/site/)and Geospatial Conservation Assessment Tool, GeoCAT (http:/ /geocat.kew.org/).In the latter, the Extent of Occurrence and Area of Occupancy of the species were traced to determine its conservation status (Bachman et al., 2011).
In Piauí, it is considered a new record (Tab. 1, Figs. 5-6).In the Franco rural community, Cocal, it was only collected in home gardens, a biocultural landscape.It was collected for the first time in 2020, and in subsequent years (2021 and 2022), it was not found during extensive botanical excursions carried out in both wet and dry seasons.The species is very similar to S. agrarium (Fig. 7), differing mainly by having a petiolar gland, serrated leaf margins, and winged suborbicular seeds.In the study area, it flowers during the rainy summer period, especially in February and March, and fruiting occurs in the months of February, March, April, May, and June.In the warm winter (dry period), the species is not found.In the state of Ceará, it was collected flowering in February, April, May, and November and fruiting in April and November (Sampaio et al., 2019).

Extension of Occurrence and Area of Occupancy
Before the inclusion of the record of S. fernandesii from Piauí, the Extension of Occurrence for this species was 478.705.565km 2 (LC category) and the Area of Occupation was equal to 64.000 km 2 (EN category).After the inclusion of the new record, the Occurrence Extension becomes 754.583.610km 2 (LC category), and the Area of Occupancy was equal 68.000 km 2 (EN category) (Fig. 9).

Habitats, morphology and peculiarities of S. fernandesii
Solanum fernandesii was collected in a rural home garden, a space structured based on traditional and sustainable management.Home gardens are traditional agricultural systems, possibly one of the oldest land use systems (Pushpakumara et al., 2012).In these spaces, a high diversity of species is cultivated and maintained for different purposes, which grow around the houses or close to them (Nair, 2006).As they are structured within properties, home gardens are seen as the first source of immediate contact between people and plants (Naigaga et al., 2021).
In the Franco rural community, home gardens represent spaces of great biological, cultural, and social importance, where local residents cultivate and maintain a high diversity of plant species, especially as food and medicinal resources (Siqueira et al., 2017(Siqueira et al., , 2020)).
Previously, the occurrence of S. fernandesii was recorded for the states of Alagoas, Bahia, Ceará, Minas Gerais, and Pernambuco (Solanaceae in Flora e Funga do Brasil, 2023;SpeciesLink, 2023).With this new record from the municipality of Cocal/PI, we have expanded the knowledge associated with the distribution of this species and regarding the Flora of Piauí.In this way, Chaves (2005) carried out a great sampling effort to document and describe the flora of Cocal from the floristic record and its economic potential.However, she did not record S. fernandesii for the study area, having found other species belonging to the Solanaceae family, such as Athenaea Siqueira, J. I. A., Menezes, I. S., Sampaio, V. S., Andrade, I. M., Lemos, J. R., Senna-Valle, L. fasciculata (Vell.)I.M.C Rodrigues & Stehmann, Physalis angulata L., S. asperum, S. crinitum, S. paniculatum, and S. paludosum.The first author of this research collected S. fernandesii between February and March 2020 in the Franco rural community while conducting an ethnobotanical investigation.
The areas where the species was collected undergo regular weeding, especially in the rainy summer.Plants that are growing spontaneously and that are considered pests or that have no use are eliminated during weeding activities.However, S. fernandesii is considered a medicinal species in the Franco rural community, and due to this, it has been kept in home gardens.In this sense, home gardens represent important spaces for the conservation of biological and cultural diversity (Nunes et al., 2007;Galluzzi et al., 2010;Amberber et al., 2014;Idohou et al., 2014;Salako et al., 2014).This species was not found outside home garden areas, as commonly occurs with S. agrarium.
Solanum fernandesii is distributed in ruderal areas, coastal tablelands, and Steppe Savanna (Sampaio et al., 2016).In Ceará state, it is found in ruderal areas and in the Seasonal Semideciduous Forest of Lowlands (Sampaio et al. 2019).In the Franco rural community, it is associated with landscapes where ruderal species commonly grow.The species is endemic to Brazil (Sampaio et al., 2016, Solanaceae in Flora e Funga do Brasil, 2022).The distribution of S. agrarium is much wider, and the species is not endemic to Brazil (Agra et al., 2009), occurring in regions that cover areas of the Neotropics, including Bolivia, Brazil, Colombia, Guyana, Jamaica, the Netherlands, and the Venezuelan Antilles, and Venezuela (Plants of the World, 2022).
Solanum agrarium is considered a ruderal plant and usually occurs in dry and open soils along roadsides, in waste places, thickets, cultivated lands, and pastures in areas with long and pronounced dry seasons (Solanaceae Source, 2022).In Brazil, this species has occurrences in Anthropic Areas, Caatinga (stricto sensu), Campo Rupestre, Cerrado (lato sensu) and Seasonal Deciduous Forest (Solanaceae in Flora e Funga do Brasil, 2023).Unlike S. fernandesii, S. agrarium has a wide distribution in the municipality of Cocal, being easily found in landscapes with a predominance of ruderal species, including home gardens, roadsides, thickets, pasture lands, etc.

Conservation status: Extension of Occurrence and Area of Occupancy
The increase in the number of records since the description of the species shows the growth in its Extension of Occurrence, 754.581.650km 2 , considered as the Least Concern category (LC), and Area of Occupation equal to 68.000 km 2 , with a category considered Endangered (EN) (Fig. 9).According to Sampaio et al. (2016), the conservation status of the species is considered Least Concern (LC), mentioning criteria such as occurrence in open anthropogenic environments and lack of records in environmental protection areas.The new record from Piauí state is within the limits of the EPA of Serra da Ibiapaba.However, it is not in an area of native vegetation.This species was also collected in a Conservation Unit, in this case, the Contendas de Sincorá National Forest (see again Tab. 1).
Based on our findings, we support that the conservation status of the species can be considered Least Concern (LC category).However, this category is related to its Extension of Occurrence, which we point out to occur in different states of Northeastern Brazil, and in Minas Gerais (Southeastern region).The species has characteristics that make its conservation status worrying in relation to its Area of Occupation, considered to be in danger of extinction (EN category).Its occurrence can be wide, however, the places where it occurs are in specific areas and few individuals are found structuring the populations.In the Franco rural community, only three individuals were found in a very specific area of a rural home garden.
In the Ceará state, S. fernandesii is found only inside the Campus do Pici, of the Federal University of Ceará, specifically in a roundabout.The records (Tab. 1, HUEFS 2503, 107061, NY 781400, CEPEC 118978, 40317) for Feira de Santana, Bahia, are also within a university Campus, as is one of the records for Alagoas (MAC 51172).Many of the records are in areas of cleared forest, roads, farms, etc. (SpeciesLink, 2023).This characteristic of being very punctual in the places of occurrence can be a decisive factor in the conservation of the species since, depending on the area where it occurring, S. fernandesii can disappear completely from the region, configuring its extinction at the local level.
In this way, in the Franco rural community, the species is more likely to disappear than S. agrarium because it occur in specific areas and is rare.In contrast, the second species S. agrarium is more frequent and has a wider distribution.On a broader scale, however, there is still no data available on population and possible threats to S. fernandesii so that we can trace a more accurate conservation status for the species. Other

Final considerations and future perspectives
We added evidence that S. fernandesii, although very similar to S. agrarium, it can be easily recognized by the petiolar gland, serrated leaf blade margin, vinaceous fruit calyx, and winged suborbicular seeds.
Our contributions support the knowledge that S. fernandesii is more associated with ruderal environments, as it was collected in a home garden, a space where many species with this profile grow.As it is collected or found only in a home garden and there are no records in Piauí outside these spaces, we presented evidence of the importance of home gardens for the maintenance of rare species, contributing to the diversity and floristic richness of Piauí.In addition to being the first record of occurrence in the state, this is the first record of the occurrence of the species associated with this type of landscape, the rural home garden inserted in the semi-arid region in the north of Piauí.
Although the literature (see Sampaio et al., 2016) treats the species with a conservation status of Least Concern (LC category), a worrying finding refers to its conservation status in relation to the Species' Area of Occupation, which, by the determined values, places it within the EN category, Endangered.The results obtained in this study, in combination with the comments presented on its frequency and habitats, suggest that the species may be more at risk of local extinction in the municipality of Cocal in relation to other species of Solanum occurring in the same municipality.We assume that extrapolating this result to all areas where the species occurs is a limiting factor, because, although the profile and described characteristics suggest a pattern for the species, we only know well the populations occurring in the states of CE and PI (Northeastern Brazil).We need complementary data to trace or suggest a more accurate conservation status for the species.
Thus, we need to advance further in our understanding of its conservation status, and for this, we need to understand why the species, despite occurring in several states of Brazil, forms very restricted populations with few individuals.Collaborative efforts between researchers from different areas with records for the species can help to solve this knowledge gap.For this, we need to better understand its reproductive biology, pollinator networks, seed dispersal, and germination, as well as the conditions and connections between the habitats where the species grows.
Our findings, ultimately, contribute to the knowledge of the Flora of Piauí, especially with the increase in the number of species in the genus Solanum, which now stands at 18 species.Piauí is a state that stands out in terms of diversity and floristic richness.Despite this, joint efforts are increasingly urgent to expand our current knowledge of the region's flora.assisted in the fieldwork, allowing us to find S. fernandesii, especially Mrs. Teresinha de Jesus Machado.Our most sincere thanks to the Botany Laboratory of the Federal University of Delta do Parnaíba (UFDPar) for their support during the conduct of the study.The authors thank the Conselho Nacional de Desenvolvimento Tecnológico e Científico (CNPq) for awarding the Master's degree scholarship (grant 134354-2019-2) to the first author.

Figure 1 .
Figure 1.The Solanum fernandesii collection's location map (a), detailing the landscape (b) where it was discovered in the Franco rural community, Cocal, Piauí, Northeastern Brazil.

Figure 2 .
Figure 2. Landscapes and vegetation details recorded in Cocal, PI: a. area of local vegetation in the dry season; b-c.detail of vegetation on top of flattened surfaces, dissected in tabular interfluves; d-j.details of the municipality's vegetation in different areas; k-l.typical vegetation in areas of lajeiros; m.Piranji River; n. view of the Algodões I Dam; o. area of carnaubas (Carnaubal).(Photos: JIA Siqueira).

Figure 8 .
Figure 8. Geographic distribution map of Solanum fernandesii in Brazil.
Sampaio & R. Moura occurs in the state of Piauí in Northeastern Brazil, thus expanding its distribution area and current knowledge about the species.It has an herbaceous to subshrub habit, is found in ruderal areas, and has great biocultural importance for the Franco rural community in the municipality of Cocal, in the north of Piauí.The number of Solanum in Cocal (Figs. 3-4) has increased to nine as a result of this new record: S. agrarium, S. americanum Mill., S. asperum, S. crinitum Lam., S. fernandesii, S. paludosum Moric., S. paniculatum L., S. rhytidoandrum Sendtn., and S. stipulaceum Willd.ex Roem.& Schult., recognized by morphological characters, according to the identification key of Solanum for the municipality of Cocal, Piauí, presented below.

Table 1 .
Selected records of Solanum fernandesii between the years 1954 to 2020, highlighting the locality, community, municipality and State (AL = Alagoas; BA = Bahia; CE = Ceará; MG = Minas Gerais; PE = Pernambuco and PI = Piauí), coordinates geographic maps and vouchers for collections available on SpeciesLink and of the present fieldwork.
species of Solanum in Cocal present conservation status with LC category, which include S. crinitum, S. paniculatum, and S. stipulaceum (IUCN, 2022) and are found within the EPA of Serra da Ibiapaba.With the exception of S. fernandesii and S. stipulaceum, the other species are widely distributed in the municipality, especially in ruderal areas.S. crinitum and S. paniculatum are found structuring large populations, especially along roadsides in the municipality.S. asperum and S. rhytidoandrum, despite being found in ruderal areas, are more frequent in areas of native vegetation, especially in open areas of lajeiros.S. fernandesii and S. stipulaceum are species that have a very punctual distribution in the municipality.Seventeen species of Solanum occur in Piauí state (Solanaceae in Flora e Funga do Brasil, 2023).Nine species of Solanum are registered in Cocal/PI, corresponding to approximately 53% of the total diversity of the genus occurring in the State.Among the species of Solanum that occur in the municipality, only S. fernandesii and S. stipulaceum are endemic to Brazil.Many of them have a wider distribution in Brazil, including S. americanum, S. asperum, S. paniculatum, and S. rhythidoandrum (Solanaceae in Flora e Funga do Brasil, 2023).