Floristic inventory of Myrtaceae of Parque Nacional do Iguaçu, Paraná, Brazil

Abstract Myrtaceae is a diverse family in Brazil and the sixth most representative family in the Atlantic Forest. In Paraná, the Parque Nacional do Iguaçu (ParNa Iguaçu) is a large National Park and also one of the largest remnants of this phytogeographic domain. The objective of the present study was to carry out a floristic inventory of the Myrtaceae of the ParNa Iguaçu, presenting an identification key to the species, illustrations, conservation status evaluation, and comments on geographic distribution and phenology. The collections were carried out between May 2019 and March 2020 in two areas composed of Seasonal Semideciduous Forest and a transitional area to Mixed Ombrophilous Forest. In addition to the samples collected by us, material from other herbaria were also examined. Twenty-five native species and one exotic species of Myrtaceae were found, distributed in seven genera. Eugenia was the most representative genus with 11 species. Of the 26 species, seven are new occurrences for ParNa Iguaçu. From the samples collected in this research and other records in the northwest and west regions of the state of Paraná, the presence of Psidium striatulum in Seasonal Semideciduous Forest is confirmed. Eugenia myrciariifolia was the only species on Brazil’s endangered species list, the IUCN conservation status of which is Endangered (EN). The other species were considered as Least Concern (LC), but some of these species are restricted to certain areas or types of vegetation. Therefore, we conclude that ParNa Iguaçu contributes to the maintenance of these species in their natural environment.


Introduction
Myrtaceae is a family with approximately 130 genera and 6,000 species (Stevens 2017) and is recognized mainly for its arboreal and shrubby habit, often smooth, exfoliating bark, leaves opposite to alternate, simple, entire, often with conspicuous oil glands; bisexual flowers with an inferior, 1-5(-18)-carpelate ovary, the presence of a hypanthium, numerous stamens and dry or fleshy fruits.Distributed predominantly in the Southern hemisphere, with a higher representation in Australia and South America, it also occurs in Africa, Southeast Asia, India, New Caledonia, and the Pacific Islands (Wilson 2011;Thornhill et al. 2015).
Through a phylogenetic analysis based on genetic sequencing data, Wilson et al. (2005) proposed a new internal classification of the family, dividing Myrtaceae into two subfamilies, Psiloxyloideae, represented by two tribes, and Myrtoideae, with 18 tribes (Wilson et al. 2022).Myrteae is the largest tribe in the subfamily Myrtoideae, with about 50 genera and 2,700 species, covering all South American native species (Stevens 2017), except Metrosideros stipularis (Hook.& Arn.) Hook.f.This tribe is characterized by the opposite leaves, free perianth, calyx lobes free or fused, tearing irregularly or forming a calyptra, numerous stamens, inferior ovary, indehiscent fleshy fruits, and one to numerous seeds with highly variable embryos (Wilson et al. 2005;Lucas et al. 2019).
In Brazil, there are 22 genera and 1.049 native species distributed across all states.Paraná, where our study was carried out, is the sixth most species-rich state (253 spp.;BFG 2015;Proença et al. 2022a).Myrtaceae are found in all phytogeographic domains, and are a significant component of the Atlantic Forest, as they provide food for fauna throughout the year (Staggemeier et al. 2017).However, this phytogeographic domain is one of the most reduced in extension (Campanili & Prochnow 2006), and in Paraná only 13.1% of its original extension remains (Fundação SOS Mata Atlântica & INPE 2019).
There are few studies specifically related to the Myrtaceae in the state of Paraná, i.e: floristic studies by Soares-Silva (2000) in the Tibagi river basin, which encompasses Cerrado, Dense Ombrophilous Forest, and Mixed Ombrophilous Forest; Romagnolo & Souza (2004, 2006), for the floodplain of the upper Paraná River, with Semideciduous Seasonal Forest formation influenced by the tributaries of the upper Paraná River; Lima et al. (2015) for Ilha do Mel, formed by Dense Ombrophilous Forest, restingas (sandy costal forests) and mangroves; Rocha (2018) for Parque Estadual de Vila Velha, composed of Cerrado and Mixed Ombrophilous Forest.Three other studies are restricted to specific genera, such as Lima et al. (2011) of Campomanesia, Sobral (2011) of Eugenia, andLannoy et al. (2021) of Myrcia.However, for the western region of the state formed predominantly by Semideciduous Seasonal Forest, such as the Parque Nacional do Iguaçu (ParNa Iguaçu), there are no floristic studies of this family.
Given the data herein presented, and the scarcity of research related to the Myrtaceae family for the study area, the objective of the present research was to provide a floristic study of the Myrtaceae in the ParNa Iguaçu.An identification key to the species is provided, as well as illustrations, conservation status, geographic distribution, phenology, and diagnostic characteristics.This research provides contributions to the knowledge of the flora of Paraná and neighboring countries (Argentina and Paraguay) as well as associated useful data for the conservation and management of this important National Park.
the Atlantic Forest: Seasonal Semideciduous Forest (SSF), with a large extension and presenting three sub-formations (Montane, Submontane, and some Alluvial regions); Mixed Ombrophilous Forest (MOF), with a smaller extension and presenting the same three sub-formations (Montane, Submontane, and some Alluvial regions) (ITCG 2009;IBGE 2012).The Köppen climate classification for the region is Cfa, characterized as a subtropical climate, with hot summers and average annual air temperatures between 20.1º C and 22ºC, with an annual rainfall ranging between 1.600 and 2.000 mm (Nitsche et al. 2019).
For this study, the park was divided into three large areas, as established by Hammes et al. (2021) (Fig. 1), and 19 trails were followed for the collection of specimens (Fig. 2): area 1, located in the northern part, a transition zone of MOF and SSF, which encompasses the administrative headquarters of ParNa Iguaçu team in Céu Azul (Fig. 2c,d); area 2, in the southern part of the park, composed exclusively of SSF, encompasses the administrative headquarters of ParNa Iguaçu team in Capanema (Fig. 2b); area 3, located in the southwest part of the park, also represented solely by SSF, where the administrative headquarters of ParNa Iguaçu team in Foz do Iguaçu is located (Fig. 2a,e).

Data collection and analysis
Between May 2019 and March 2020, 17 collecting field expeditions were carried out.At least three branches of fertile individuals were collected, which were described, photographed in the field, and herborized according to Bridson & Forman (2010).The samples were incorporated into the UNOP herbarium, and the duplicates were sent to the EVB, HCF, HUFSJ, MBM, and UB herbaria (acronyms according to Thiers, continuously updated).In addition to these, specimens from the BHCB, CGMS, EVB, FUEL, FURB, HCF, HUCS, HUEFS, HUEM, MBM, NY, SP, U, UB, UPCB, and UNOP herbaria.The samples were analyzed with the aid of a stereoscope, and precise identification reached consulting specific literature (Landrum 1981;Lannoy et al. 2021;Lima et al. 2011;Proença et al. 2022b;Sobral 2003Sobral , 2011)).The correct spelling of scientific names and the species authors were checked against the International Plant Names Index (IPNI 2021) and Proença et al. (2022a).For this study, the samples were treated at the species level, disregarding varieties and for each area a single voucher was selected; other vouchers are listed in Appendix S1, available on supplementary material <https://doi.org/10.6084/m9.figshare.22564264.v1>.
The botanical illustrations were based on selected characteristics of the identification key that were considered important for species recognition.They were illustrated in pen and ink from the observation of exsiccatae or photos of the plants in the field.Morphological terms follow Radford et al. (1974), Stearn (1992), andSobral (2003).For each species complementary literature is cited; the criteria used to select this literature was that it must include a morphological description of the species.
Information on geographic distribution and the phytogeographic domains the species inhabit were obtained from the Flora e Funga do Brasil platform (Proença et al. 2022a) and Plants of the World Online (POWO 2022).Data on phenology, elevation, and areas of occurrence in ParNa Iguaçu were based on the samples collected and on the information on the labels of analyzed material.
The species conservation status was verified by consulting the IUCN Red List of Threatened Species (IUCN 2021) and the National Flora Conservation Center (CNCFlora 2012).For the non-evaluated species, a preliminary assessment was made using the GeoCAT tool created by Bachman et al. (2011), which follows the IUCN Red List Criteria Application Guidelines for Regional and National Levels (IUCN 2012).The data used in this analysis was taken from the speciesLink database, filtering only the records from Brazil, with original coordinates, and removing duplicate records.

Results and Discussion
Twenty-six species of Myrtaceae were recorded for the ParNa Iguaçu, distributed in seven genera .All species found belong to subfamily Myrtoideae and tribe Myrteae (Wilson et al. 2005).Eugenia was the most representative genus with 11 species, followed by Myrcia with five species, Campomanesia and Psidium with three species each, Myrceugenia with two species, and Blepharocalyx and Plinia with one species each.
Blepharocalyx salicifolius occurs in Ecuador, Peru, Bolivia, Brazil, and Argentina (POWO 2022).In Brazil this species is distributed in the Northeast, Central-West, Southeast and South regions (Vasconcelos & Proença 2022).In the ParNa Iguaçu it is registered in areas 2 and 3, in SSF Submontane formation.It was collected with flowers in November and fruits in January.The species is evaluated as Least Concern -LC (CNCFlora 2012).
The popular names of the species are: murta, murteira.
Complementary bibliography: Landrum (1986); Santos & Sano (2012); Lima et al. (2015); Stadnik et al. (2018).Bolivia, Brazil and Argentina (POWO 2022).In Brazil this species is distributed in all regions (Oliveira et al. 2022).In the ParNa Iguaçu it was registered in areas 1 and 3 in SSF Montane and Submontane formations.It was collected with flowers and fruits in November.It is suggested that this species should be rated as Least Concern -LC, due to the EOO higher than 20,000 km² (5,989,732.280 km²).
Campomanesia guazumifolia occurs in Brazil and Paraguay (POWO 2022).In Brazil this species is distributed in the Northeast, Central-West, Southeast and South regions (Oliveira et al. 2022).
In the ParNa Iguaçu it was registered in all areas, in SSF Submontane and MOF Montane, Submontane and Alluvial formations.It was collected with flowers in February and October and fruits in January.Campomanesia guazumifolia is evaluated as Least Concern -LC (IUCN 2021).
The popular names of the species are: setecapotes, capoteira.

Campomanesia xanthocarpa occurs in
Brazil and Argentina (POWO 2022).In Brazil this species is distributed in the Southeast and South regions (Oliveira et al. 2022).In the ParNa Iguaçu it was registered in all areas, in SSF Submontane, SSF Montane and MOF Montane formations.It was collected with flowers in August and October and fruits in November.The species is evaluated as Least Concern -LC (CNCFlora 2012).
The popular name of the species is: gabiroba.

Fig. 5h
Eugenia burkartiana is recognized by the sessile to short-pedicellate flowers and by the marginal vein 3 to 5 mm from the leaf margin.

Caxambu et al. 7862 (HCF!, MBM!).
Eugenia burkartiana occurs in Brazil, Argentina and Paraguay (POWO 2022;Sobral 2011).In Brazil this species is distributed in the Southeast and South regions (Mazine et al. 2022).In the ParNa Iguaçu it was registered in all areas, in SSF Submontane and MOF Montane and Alluvial formations.It was collected with flowers in February, March and April and fruits in July.The species is evaluated as Least Concern -LC (CNCFlora 2012).
The popular name of the species is: guamirim.

Eugenia myrcianthes
In the ParNa Iguaçu it was registered in all areas, in SSF Submontane and MOF Montane formations.It was collected with flowers in August and October and fruits in October.Eugenia myrcianthes is evaluated as Least Concern -LC (IUCN 2021).
The popular name of the species is: pessegueiro-do-mato.
Selected material: Área 1, Rio Floriano, 19.III.2004, fl Eugenia paracatuana occurs in Brazil and Paraguay (POWO 2022;Sobral 2011).In Brazil it is distributed in the Central-West, Southeast and South regions (Mazine et al. 2022).In the ParNa Iguaçu it was registered in areas 2 and 3, in SSF Submontane and SSF Alluvial formations.It was collected with flowers in August, September and October and fruits in September and December.It is suggested that this species should be rated as Least Concern -LC due to the EOO higher than 20,000 km² (1,037,659.626 km²).
The popular name of the species is: cambuí.This species is native to South America but widely cultivated worldwide, especially in Africa, Southeast Asia and Australasia (POWO 2022;Sobral 2011).In Brazil it is distributed in the Northeast, Central-West, Southeast and South regions (Mazine et al. 2022).In the ParNa Iguaçu it was registered in areas 1 and 3, in SSF Submontane and MOF Montane formations.It was collected with flowers in June and fruits in February.Eugenia uniflora is evaluated as Least Concern -LC (IUCN 2021).
The popular names of the species are: pitanga, pitangueira.
Myrceugenia euosma occurs in Brazil and Argentina (POWO 2022).In Brazil it is distributed in the Southeast and South regions (Vieira & Meireles 2022).In the ParNa Iguaçu it was registered only in area 1, in MOF Alluvial formation.It was collected with flowers and fruits in February.It is suggested that this species should be rated as Least Concern -LC due to the EOO higher than 20,000 km² (374,580.443 km²).
The popular names of the species are: cambuizinho, guamirim-branca.
Myrceugenia glaucescens occurs in Paraguay, Argentina, Uruguay and Brazil (POWO 2022).In Brazil it is distributed in the Southeast and South regions (Vieira & Meireles 2022).In the ParNa Iguaçu it was registered in areas 1 and 3, in SSF Submontane, SSF Alluvial and MOF Montane formations.It was collected with flowers in October and fruits in May and December.Myrceugenia glaucescens is evaluated as Least Concern -LC (CNCFlora 2012).
The popular names of the species are: cambuí, guamirim, cambuizinho.
Myrcia glomerata occurs from Ecuador, Bolivia and Brazil to Argentina (POWO 2022).In Brazil it is distributed in the Southeast and South regions (Santos et al. 2022) (2021) there are no consistent diagnostic features that clearly distinguish M. palustris from M. hartwegiana specimens from Paraná, and further studies are needed to better distinguish these species.
Selected material: Área 1, trilha do Rio Butu próximo à lagoa, 739 m, 25º5 '22''S, 53º40'9''W, 13.XII.2019, fl., L.H.S.M. Conceição et al. 226 This species in endemic to Brazil and is distributed in the Southeast and South regions (Santos et al. 2022;POWO 2022).In the ParNa Iguaçu it was registered only in area 1, in SSF Montane and MOF Montane formations.It was collected with flowers in December and fruits in October.It is suggested that this species should be rated as Least Concern -LC due to the EOO higher than 20,000 km² (743,903.782km²).
The popular name of the species is: guamirim.DC., Prodr. 3: 251. 1828. Figs. 4d; 6f This species is recognized by the moderately to strongly discolored leaves, flowers ranging from tetramerous to pentamerous in the same individual, and unequal-sized calyx lobes.Myrcia oblongata occurs in Brazil and Argentina (POWO 2022).In Brazil it is distributed in the Southeast and South regions (Santos et al. 2022).In the ParNa Iguaçu it was registered only in area 2, in SSF Submontane formation.It was collected with flowers in December and fruits in November.Myrcia oblongata is evaluated as Least Concern -LC (CNCFlora 2012).

Fig. 4c
Myrcia palustris is recognized by the leaves with flat margins and angulation of the secondary veins in relation to the central one of approximately 45-50º.However, this species is very close to M. hartwegiana (see comments under that species).

Myrcia palustris occurs in
The popular names of the species are: cambuizinho, pitangueira-do-mato.This species occurs in Argentina, Bolivia, Brazil, Paraguay and Uruguay (POWO 2022).In Brazil it is distributed in all regions (Santos et al. 2022).In the ParNa Iguaçu it was registered in all areas, in SSF Submontane, SSF Montane and MOF Montane formations.It was collected with flowers in February, August and October and fruits in December.Myrcia selloi is evaluated as Least Concern -LC (IUCN 2021).
The popular names of the species are: cambuí, cambuizinho-vermelho.
Fig. 4e-f This species is recognized by the leaves with acuminate to long acuminate apex, tetramerous flowers, calyx lobes triangular and racemose inflorescences.
Plinia rivularis occurs from Trinidad and Tobago to Argentina (POWO 2022).In Brazil it is distributed in all regions (Stadnik et al. 2022).In the ParNa Iguaçu it was registered in all areas, in SSF Submontane, SSF Montane and MOF Montane formations.It was collected with flowers in August and September and fruits in October and November.Plinia rivularis is evaluated as Least Concern -LC (IUCN 2021).
The popular names of the species are: guaburiti, guapuriti.

24.
Psidium guajava L., Sp. Pl. 1: 470. 1753. Fig. 6i This species is recognized by the leaves with 12-17 pairs of veins and abundant translucent dots, easily seen against the light under a stereoscopic microscope.Its ripe fruits have a green to yellowgreen external color and the pulp is whitish to pink.In Area 1 a sterile individual was registered on the Manoel Gomes trail.
Out of the 26 species found in the study area, 25 are native to Brazil, and only P. guajava is exotic, currently considered naturalized (Proença et al. 2022a).However, despite being considered naturalized, this species appears in the park as a casual exotic (Richardson et al. 2000;Pysek et al. 2004;Moro et al. 2012), since it was in a reproductive form, but with few individuals, not enough to be considered a viable population.This species was recorded in a few trails in the park, which is positive in terms of conservation, since P. guajava has allelopathic potential over other species (Chapla & Campos 2010;Kawawa et al. 2016), which can negatively affect natural ecosystems.
Before this study, 28 species were recorded for the park, in the management plan (IBAMA, 1999), phytosociological studies (Gris & Temponi 2017;Gris et al. 2014;Souza et al. 2019), and in a checklist for ParNa Iguaçu (Trochez et al. 2017 which also has a mucronate apex but smaller (up to 1 mm), tetramerous flowers arranged in fascicles and fruits with a circular scar originating from the abscission of the prolonged hypanthial tube (Tab.2).
These results were compared with the management plan of the Parque Nacional Iguazu, a contiguous conservation unit in Argentina (Ministerio de Ambiente y Desarrollo Sustentable 2017), which listed 17 species of Myrtaceae (Tab. 3) most of which were also recorded in our study.Six of them were not found in the ParNa Iguaçu (Brazil): Myrciaria tenella (DC.)O.Berg, that has a wide distribution in South America; Eugenia pitanga (O.Berg) Nied., and Myrcianthes pungens (O.Berg) D.Legrand that are distributed from Bolivia to Argentina; Eugenia mansoi O.Berg, and Eugenia uruguayensis Cambess., that have a more restricted distribution, extending from Brazil to Argentina (POWO 2022).These species may occur in ParNa Iguaçu, particularly M. pungens that was collected 5 km from the park border (see paragraph above) but the confirmation of these identifications was not possible because the management plan of the Parque Nacional Iguazu also does not include herbarium vouchers for the listed species.
The conservation status of the four nonevaluated species was assessed using GeoCAT, and all of them were classified as Least Concern (LC) according to the IUCN criteria (2012).Twenty species had already been evaluated by CNCFlora (2012) and IUCN (2021), and were also categorized as Least Concern (LC) due to their wide distribution across phytogeographic domains, Brazilian vegetation formations, and conservation units or for having large populations in most cases.However, we highlight the species E. myrciariifolia, considered Endangered (EN) that occurs in ParNa Iguaçu in areas 1 and 2. This species is endemic to Paraná and found only in SSF (Mazine et al. 2022).The Forest has suffered a significant reduction in its natural area, which may have reduced their population into subpopulations, and only one of these occurs in conservation units such as the ParNa Iguaçu (CNCFlora 2012).In addition, this species was not collected during our expeditions and the

Total species 12
Table 3 -Total Myrtaceae species presented in the management plan for the Parque Nacional Iguazu, Argentina (Ministerio de Ambiente y Desarrollo Sustentable 2017) and in the second column the species also found in the ParNa Iguaçu, Brazil.

Figure 2 -
Figure 2 -ParNa Iguaçu trails -a.view of the Iguaçu Falls while walking in the Cataratas trail; b. banks of Iguaçu river, Brazilian side; c.Cachoeira do Rio Azul trail; d.Manoel Gomes trail; e. end of Macuco Safari trail, banks of Iguaçu river with Psidium striatulum growing among the rocks.

3 .
Campomanesia guazumifolia (Cambess.)O.Berg, Linnaea 27(4): 434.1856.Fig.5d-fThis species distinguishes from the other Campomanesia in the ParNa Iguaçu by the totally closed calyx, which is deciduous during fruiting, and by the fruit covered by trichomes.In addition, its leaves also present abundant trichomes, especially on the abaxial surface, and welldeveloped secondary and tertiary veins.

6 .
(Mazine et al. 2022011)dr.3:283.1828.Fig.5i-jEugeniaflorida is recognized by the racemose inflorescences and leaves with the first pair of secondary veins not confluent with the marginal veins formed by the other veins.Eugenia florida occurs from Nicaragua to Argentina(POWO 2022;Sobral 2011).In Brazil it is distributed in the North, Northeast, Central-West, Southeast and South regions(Mazine et al. 2022).In the ParNa Iguaçu it was registered in areas 1 and 3, in SSF Submontane, Montane and Alluvial formations.It was collected with flowers in August and September and fruits in October and November.Eugenia hiemalis occurs from Bolivia to Brazil and Argentina (POWO 2022; Sobral 2011).In Brazil it is distributed in the Central-West, Southeast and South regions(Mazine et al. 2022).In the ParNa Iguaçu it was registered in all areas, in SSF Submontane, SSF Alluvial and MOF Alluvial formations.It was collected with flowers in March and April and fruits in October and November.

8 .
(Bünger 2015;Bünger et al. 2016;Mazine et al. 2022sspecies is easily recognized by the cordate bracteoles and well-developed calyx lobes (around 10 mm), persistent until fruiting.Eugenia involucrata occurs from Bolivia to Brazil and Argentina (POWO 2022).In Brazil it is distributed in the Northeast, Central-West, Southeast and South regions(Bünger 2015;Bünger et al. 2016;Mazine et al. 2022).In the ParNa Iguaçu it is registered in all areas, in SSF Submontane, SSF Alluvial, MOF Montane and MOF Alluvial formations.It was collected with flowers in September and October and fruits in October.Eugenia involucrata is evaluated as Least Concern -LC (IUCN 2021).
Selected material: Myrcia hartwegiana is recognized by the leaves with revolute margins and angulation of the secondary veins in relation to the midvein of approximately 60°.According to Lannoy et al.
(Proença etProença et al. 2022bn all regions(Proença et al. 2022b).In the ParNa Iguaçu it was registered in all areas in SSF Submontane, SSF Alluvial and MOF Montane formations.It was collected with flowers in September and October and fruits in April and October.Psidium guajava is evaluated as Least Concern -LC (IUCN 2021).Área 3, costão rochoso próximo  ao Rio Iguaçu, 110 m, 25º38'50''S, 54º27'30''W,  15.II.2020, fr., L.H.S.M. Conceição et al. 254 (UNOP!).guineense occurs from Mexico to Argentina (POWO 2022).In Brazil it is distributed in all regions(Proença et al. 2022b).In the ParNa Iguaçu it was registered only in area 3, in SSF Submontane and Alluvial formation.It was collected with flowers in February and April and fruits in February and June.Psidium guineense is evaluated as Least Concern -LC (IUCN 2021).Psidium striatulum occurs from North America to Bolivia and Brazil.In Brazil it is distributed in all regions, and Paraná is the southern limit of its distribution(POWO 2022;Proença et al. 2022b).In the ParNa Iguaçu it was registered only in area 3, in SSF Alluvial formation.It was collected with flowers in May and fruits in February.Psidium striatulum is evaluated as Least Concern -LC (IUCN 2021).