Flora of Ceará state, Brazil: Evolvulus (Cresseae, Convolvulaceae)

Abstract We present the taxonomic treatment of Evolvulus in the state of Ceará, as part of the project “Flora do Ceará: Knowing to conserve”. The study was based on the floristic-morphological analysis of specimens deposited in the ASE, CEN, EAC, ESA, HCDAL, HST, HUEFS, HUVA, HVASF, IPA, PEUFR, and UFP herbaria, specialized bibliography, typus collections available on on-line platforms, collections and field observations. In Ceará, we registered 13 species of Evolvulus: E. anagalloides, E. cardiophyllus, E. eleaegnifolius, E. ericifolius, E. filipes, E. glomeratus, E. gypsophiloides, E. linoides, E. nummularius, E. ovatus, E. phyllanthoides, E. pterocaulon, and E. sericeus. Of these, ten occur in protected areas from Ceara state. The greatest species richness for the genus (10) was registered in the open crystalline caatinga. Additionally, we present an identification key, morphological descriptions, geographic distribution, taxonomic and ecological comments, phenology and illustrations of the diagnostic characters of the species.

According to Souza & Lorenzi (2012), some species stand out for their ornamental potential, such as E. glomeratus and E. pusillus Choisy, which are grown in gardens.Ooststroom (1934), in his monograh, reports the use of E. nummularius for haemorrhagia in Madagascar and of E. alsinoides L. in natural medicine in British India.Patil (2009) highlights the medicinal potential of the latter species, as it has anxiolytic activity.
In Brazil, the genus has been studied in local, state and regional floras surveys, including Ferreira et al. (2014) who cited nine species for the Southern region; Silva (2008) listed 15 and 13 species for the state of São Paulo and the Federal District, respectively; Santos & Buril, (2020) cited 17 species for Pernambuco, and Junqueira & Simão-Bianchini (2006) who cited 12 species for the municipality of Morro do Chapéu (Bahia).Additionally, Silva (2013) performed the taxonomic revision of Evolvulus section Phyllostachyi Meisn., and accepted 17 species.Specifically, in Ceará, studies focusing on Evolvulus species are scarce and rarely mentioned in floristic surveys (Ribeiro-Silva et al. 2012;Loiola et al. 2015Loiola et al. , 2020;;Silveira et al. 2020a, b) or in studies that focused on Convolvulaceae (Santos et al. 2020).
Despite the high representativeness of Evolvulus in Brazil, the knowledge about its diversity in Brazilian flora is still poorly known, evidenced by its erroneous collections, making it difficult to access its taxonomic richness and geographical distribution.Considering this, we present the floristic-taxonomic treatment of Evolvulus in Ceará state, which aims to facilitate the correct recognition of the species and provide information on their phenological period, distribution and morphology.

Material and Methods
C e a r á s t a t e o c c u p i e s a n a r e a o f approximately 148,825.6 km 2 , corresponding to 1.74% of the national territory and 9.57% of the Northeast region, being the fourth largest state in the region (IPECE 2013).It is limited to the North by the Atlantic Ocean, to the South by Pernambuco, to the East by Rio Grande do Norte and Paraíba, and to West by Piauí (IPECE 2013).According to Moro et al. (2015) (Figueiredo 1997) (Fig. 1).
This study was based on the consultation of specialized bibliography (Meisner 1869;Ooststroom 1934;Silva 2013), analysis of type collections and specimens deposited in the ASE, CEN, EAC, ESA, HCDAL, HST (Herbarium Sérgio Tavares), HUEFS, HUVA, HVASF, IPA, PEUFR, and UFP herbaria (acronyms according to Thiers, continuously updated).The samples were processed according to the usual taxonomy techniques (Mori et al. 1989) and incorporated into the HUVA, with duplicates sent to the EAC and HUEFS herbaria.Identifications were made based on specialized bibliography (Ooststroom 1934) and analysis of type collections (NY and R) available on online database (<https://plants.jstor.org/>).The binomials are according to the IPNI (2018).The morphological descriptions were standardized according to Harris & Harris (2001).Data regarding the type of habit, flowering and fruiting period were obtained from exsiccate labels and/or from the field observations.Data about geographic distribution in the world and Brazil were obtained according to specialized literature (Ooststroom 1934) and Flora of Brazil (Simão-Bianchini & Silva 2020), respectively.The geographic distribution maps were prepared using ArcGIS software, version 7.4 (Hijmans et al. 2005), based on mainly records with original geographic coordinates.For records without collections site coordinates associated, those of another species collected at the same location were used through the geoLoc tool (CRIA 2018).For the species distribution, the phytogeographic classification of Figueiredo (1997) modified by Moro et al. (2015) was used.Illustrations were made from exsiccates and samples in alcohol, contemplating the main characters that identify the taxa.Among the phytoecological units in Ceará, Crystalline Caatinga presents the highest species diversity for the genus (10), representing 77% of the total species diversity in Ceará.The Costal Vegetation Complex and the Sedimentary Wet Forest present six species each, equating to 46% of the total species in the state (Tab.1).In the Wet Forest of Crystalline, and in Mangrove no species of Evolvulus was found.
Evolvulus anagalloides is easily recognized by its sarmentose stem, sessile and ovate leaves.It is similar to E. nummularius by sharing the prostrate habit, but differs from it by its sarmentose stem (vs.stoloniferous stem).In the R herbarium, there are two specimens collected by Freire Allemão (number 1103), who considered them as E. anagalloides.However, one of them is attributed to E. anagalloides (R 45710) and the other to E. sericeus (R 40671), and are distinguished by their registration numbers.Freire Allemão, in 1859, identified these specimens as the same species probably because they share sarmentose stems and ovate leaf blades.
This species is endemic to Brazil, with continuous distribution from Maranhão, Piauí, Ceará, Pernambuco, Bahia and Minas Gerais, in the Caatinga.In Ceará state, this species occurs in Caatinga vegetation with sedimentary and crystalline origin; sedimentary Wet Forest, and in Coastal Vegetation Complex (Fig. 1).This species was found in Environmental Protection area (APA in portuguese) Serra da Ibiapaba and in the FLONA (National Forest) from Araripe.
The species was collected with flowers from February to June; and with fruits from February to March.Schltdl., Linnaea 26: 653. 1855.

Freire Allemão & M. Cysneiro 1106 (R).
Evolvulus cardiophyllus is a morphologically well-defined species, being characterized by having flowers isolated, axillary distributed along the  Rodriguésia 74: e00602021.2023 branches, leaf blade with both surfaces pilose and hypocrateriform corolla.It can be confused with E. latifolius which occurs in surrounding states, due to its ovate to lanceolate leaf blade, but it differs from this by the sepals with acuminate apex (vs.falcate to acute in E. latifolius), epidermal vesicles absent on the anthers (vs.present) and hypocrateriform corolla (vs.funnel-shaped).
This species is widely distributed, occurring in Mexico, Venezuela, Colombia and Brazil, where it presents a disjunct distribution, occurring in the north in Acre, Amazonas and Roraima, and continuously into Piauí, Ceará, Bahia, Minas Gerais and Rio de Janeiro, and further south into Paraná.In Ceará, this species has a disjunct distribution between Caatinga vegetation and the Coastal Vegetation Complex (Fig. 1).This species occurs in FLONA from Araripe and in RPPN Serra das Almas.
The species was collected with flowers in March, May and June; and with fruits in March.Evolvulus eleaegnifolius is characterized by axillary dichasium with long peduncles distributed from the middle to the apex of the branches, discolorous leaf blade and entire corolla.It is similar to E. linoides by its linear and discolorous leaf blade, but differs by its leaf margin flat (vs.revolute in E. linoides) and entire corolla (vs.deeply lobed).

Evolvulus elaeagnifolius
It is endemic to Brazil with continuous distribution from Ceará, Pernambuco, Bahia to Minas Gerais, in the Caatinga.In Ceará, this species occurs in Caatinga vegetation with sedimentary and crystalline origin; in Cerrado and Cerradão, and Dry and Wet Forests with sedimentary origin (Fig. 1).This species occurs in the APA Serra da Ibiapaba and in the RPPN Serra das Almas.
The species was collected with flowers in February, March and May; and with fruits in May.This species is characterized by its discolorous leaf blade, dichasium at the apex of the branches and sepals with obtuse apex.It is similar to E. gypsophiloides Moric.by sharing discolorous leaf blade, dichasium at the apex of the branches, but differs by its sepals with obtuse apex (vs.acuminate).

Evolvulus ericifolius
This species is endemic to Brazil, it has continuous geographical distribution from Maranhão, Piauí, Ceará, Pernambuco, Bahia, Minas Gerais, Espírito Santo, Rio de Janeiro, as well as in Tocantins, Goiás and Mato Grosso, in the Caatinga and Cerrado.In the study area, this species is restricted to the Coastal Vegetation Complex, in Cerrado stricto sensu in the municipality of Granja (Fig. 1) from an unprotected area.
The species was collected with flowers in March, May and June; and with fruits in March.
Evolvulus filipes is easily identified because it is an herb with erect or decumbent stem, concolorous leaf blade, dichasium with long peduncle distributed along the branches, and corolla < 5 mm diam.In several analyzed specimens, E. filipes has been misidentified as E. linarioides, probably because they share a decumbent stem, leaf blade elliptical, sericeous and concolorous.However, E. filipes differs by the pedicel shorter than the floral peduncle (longer than the peduncle in E. linarioides) and corolla < 0.5 cm diam.(vs.1-1.2 cm diam.).
Evolvulus filipes is widely distributed, from Mexico to Paraguay.In Brazil, it has a continuous distribution from the Amazonas to Paraná.In Ceará, this species occurs in Caatinga and Dry Forest; in Sedimentary Dry Forest, Carnaubal, and in the Coastal Vegetation Complex (Fig. 1).This species occurs in the Estação Ecológica de Aiuaba and in the RPPN Serra das Almas.
Evolvulus glomeratus is widely distributed, occurring throughout South America, except for Chile and Peru.In Brazil, it is registered in all regions and phytogeographic domains.In Ceará, this species occurs in Caatinga vegetation on crystalline lands; Cerrado and Cerradão, Sedimentary Dry Forest and Coastal Vegetation Complex (Fig. 1).There are populations of this species in Aiuaba Ecological Station.
Evolvulus gypsophiloides is characterized by having discolorous leaf blade, dichasium at the apex of the branches, and sepals with acuminate apex.Its similarity with E. ericifolius is discussed under the comments of this species.
This species is endemic to Brazil, occurring continuously in Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Bahia, Minas Gerais, Rio de Janeiro, as well as in Goiás and Mato Grosso, in Caatinga and Cerrado.In Ceará state, this taxon occurs in Caatinga vegetation on crystalline lands, Carnaubal, and the Coastal Vegetation Complex (Fig. 1).This species was collected in the RPPN Serra das Almas.
This species is characterized by its leaf blade linear, revolute margins, dichasium with long peduncle distributed from the middle to the apex of the branches, and corolla deeply lobed.It is similar to E. eleaegnifolius, but differs as shown in this species' comment.
This species has disjunct geographical distribution between Bolivia and Brazil.In Brazil, it has a continuous distribution from Ceará, Rio Grande do Norte, Pernambuco, Bahia, Minas Gerais and Mato Grosso.In Ceará, this species has disjunct distribution between the Crystalline Caatinga and Sedimentary Wet Forest (Fig. 1).This species occurs in the RPPN Serra das Almas.
The species was collected with flowers in January and May; and with fruits in May.
In the study area, this species is easily recognized by its stoloniferous stem and orbicular leaf blade.The resemblance to E. anagalloides is discussed before, under the comments of this species.
Evolvulus nummularius has a pantropical distribution.In Brazil, it is found from Amazonas to Paraná.In the study area, it occurs in Caatinga and Dry Forest vegetation of crystalline origin, and Wet Forest of sedimentary origin (Fig. 1).This species occurs in the Ubajara National Park and RPPN Serra das Almas.
The species was collected with flowers from May to July; and with fruits in June.Fernald.,Proc. Amer. Acad. Arts 33(5): 89.1897.
This species has a wide geographical distribution, occurring from southern Mexico, Guatemala, Venezuela, Colombia, and Brazil.In Brazil, it reported to northern Amazonas from Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Bahia, Alagoas, Minas Gerais and Goiás states, in the Amazon, Caatinga and Cerrado.In Ceará, this species is recorded in Crystalline Caatinga, Crystalline Dry Forest, and in the Coastal Vegetation Complex (Fig. 1).One population of this species was registered in the FLONA from Araripe.
The species was collected with flowers in January, April to July; and with fruits in January, April to June, and August.This species is morphologically well defined and can be characterized by its leaf blade ovate to lanceolate, dichasium axillary with short peduncle concentrated in the terminal portions of branches.
This species is endemic to Brazil, with continuous distribution from Pará, Maranhão, Piauí, Ceará, Rio Grande do Norte, Pernambuco, Bahia, Sergipe, Minas Gerais and Rio de Janeiro, in the Caatinga, Cerrado and Atlantic Forest.In Ceará, this species occurs in Caatinga vegetation and Dry Forest of Crystalline origin, and Wet Forest of sedimentary origin (Fig. 1).This species was collected in the APA Serra da Ibiapaba, Ecological Station de Aiuaba and in the RPPN Serra das Almas.
Evolvulus pterocaulon is easily recognized by the following set of characters: winged stems, decurrent leaf base, flowers congested at the apex of the branches and hypocrateriform corolla.Its resemblance to E. glomeratus is discussed under the comments of this species.
This species occurs in Bolívia, Venezuela and Brazil.In Brazil, it is widely distributed, occurring in Tocantins, Maranhão, Piauí, Ceará, Alagoas, Sergipe, Bahia, Goiás, Mato Grosso do Sul, Mato Grosso, Minas Gerais, Espírito Santo and São Paulo.In Ceará, this species is found on the Caatinga vegetation of crystalline origin and Wet Forest of sedimentary origin (Fig. 1).Populations of this species were collected in RPPN Serra das Almas.
The species was collected with flowers in May and July; and with fruit in July.
This species has wide geographical distribution, occurring in the Southern United States, throughout Central America, Bolivia, Northern Argentina and Brazil.In Brazil, it is recorded in all regions and phytogeographic domains.In Ceará, only the material collected by Freire Alemão & M. Cysneiros 1103 deposited in R, from 1859, was traced.No other records of this species have been found so far in the state.
The species was collected with flowers in April.
, Ceará has two large geological domains, one of sedimentary origin divided into five relief units called Planície Costeira, Planície Fluvial, Chapada do Araripe, Chapada do Apodi and Serra da Ibiapaba; and another of crystalline origin, divided into two relief units known as Depressão Sertaneja and Residual Massifs.
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