Salvinia (Salviniaceae) in southern and southeastern Brazil—including new taxa, new distribution records, and new morphological characters

Abstract

In this work, the taxonomic study of Salvinia from the southern and southeastern regions of Brazil is presented. We analyzed materials from herbaria BHCB, BHZB, CAY, CESJ, CVRD, DIAM, ESAL, FLOR, FUEL, FURB, HAS, HB, HBR, HUFU, HURG, ICN, MBM, MBML, OUPR, PACA, R, RB, SJRP, SP, SPF, SPFR, UEC, UPCB, VIC, VIES, plus online images of types, and field studies. In southern and southeastern Brazil, nine taxa of Salvinia occur, of which two are new to science: S. auriculata var. major C.V. Miranda & Schwartsb., var. nov., S. biloba Raddi, S. cucullata Roxb., S. × delasotae C.V. Miranda & Schwartsb., hybr. nov., S. herzogii de la Sota, S. oblongifolia Mart., S. minima Baker, S. molesta D.S. Mitch., and S. radula Baker. Salvinia cucullata and S. × delasotae are cultivated taxa, not occurring naturally. Based on studies of plants from French Guiana, we concluded that S. auriculata s. str. (= S. auriculata var. auriculata) does not occur in southern and southeastern Brazil. Updated nomenclatural headings, descriptions, illustrations, key, and maps of distribution of all taxa are also presented.

1 Introduction

Salvinia Ség. is a genus of floating, aquatic ferns, comprising circa a dozen species worldwide, of which ca. 8–10 occur in Brazil (Tryon and Tryon 1982; Forno 1983; Moran 1995; Sota 2001; Smith et al. 2008; Prado et al. 2015; Miranda and Schwartsburd 2016; PPG I 2016). In Brazil, they are vulgarly named as “orelha-de-onça” (“ear of jaguar”). Salvinia species are characterized by producing three leaves per node, two of which are floating green and one that is submerged, brown, highly dissected, root-like and bears the sori in an axis called sorophore (Nagalingum et al. 2006). Salvinia species also have unique hair systems on leaves that allow them to be excellent floaters (e.g., Barthlott et al. 2009, 2010). In addition to these characters, Salvinia species also have apomorphies common to the other Salviniales, such as heterospory and endosporic gametophytes.

Salvinia molesta D.S. Mitch., the Kariba weed, is a famous aggressive invasive plant that has entered IUCN’s list of 100 most dangerous alien species, and has naturalized worldwide, in countries such as Australia, India, Indonesia, South Africa, USA, and Zambia. There, S. molesta forms mats and covers whole lake areas, harming local flora and fauna, and also bringing damage to people that depend on water economy (Forno and Harley 1979; Forno 1983; Oliver 1993; Julien et al. 2002; Moran 2004). This species with hybrid origin is native from southern Brazil and was initially sold as aquatic ornamental and has rapidly and efficiently escaped from cultivation, due to the high rates of growth and vegetative reproduction (Mitchell 1970; Mitchell and Tur 1975; Mitchell 1978; Room 1986; Room and Thomas 1986; Julien et al. 2002). Ironically, S. molesta is apparently not able to reproduce sexually, being an allopentaploid taxon (Schneller 1980, 1981; Sota 2001; Moran 2004; Miranda and Schwartsburd 2016).

On the other hand, Salvinia species are of great interest to naval engineering, due to the air retention ability of their hair systems. The hairs have hydrophilic tips and super-hydrophobic bodies, forming an air layer within them (Barthlott et al. 2009, 2010). Some species, for example Salvinia cucullata Roxb., are also sold as aquatic ornamentals, easily found in Brazilian Web sites. Finally, some species of Salvinia can be used in phyto-remediation of water bodies contaminated with heavy metal, such as cadmium, chromium, and lead (Almeida 2009; Pereira et al. 2012).

The taxonomy of Salvinia in Brazil

– Salvinia was originally described by the French botanist Jean-François Séguier, honoring the Italian Botanist A. M. Salvini (Séguier 1754). The first work to treat a Brazilian Salvinia was that of Willdenow (1810), who described S. rotundifolia Willd. from an unspecified location in Brazil. Then, Raddi (1819) listed S. rotundifolia to the state of Rio de Janeiro. In a second edition of Brazilian ferns, Raddi (1825) further described S. biloba Raddi from this state. Later, Martius (1834) described S. oblongifolia Mart. from the state of Pará.

Fée (1869), in the first comprehensive Brazilian fern flora, considered three species of Salvinia there: S. hispida Kunth, S. oblongifolia, and S. rotundifolia, stating that S. biloba would not be much different from S. rotundifolia. Kuhn (1884), in the monumental Flora Brasiliensis, also considered three species from Brazil, but only one in common with Fée (1869): S. auriculata Aubl. (with S. biloba, S. hispida, and S. rotundifolia in synonymy), S. oblongifolia, and the newly described S. sprucei Kuhn.

Baker (1886), in his synopsis of the “Rhizocarpeae,” listed Salvinia auriculata var. auriculata, S. auriculata var. olfersiana Baker, S. oblongifolia, S. minima Baker, S. radula Baker, and S. sprucei to Brazil. Baker (1886) also considered S. biloba, S. hispida, and S. rotundifolia synonyms of S. auriculata var. auriculata.

The species with fouet-like hair systems (= egg beater like) were initially treated as only one accepted taxon, Salvinia auriculata, by Herzog (1935). Later, Sota (1962a, b, c) recognized three species in this complex: S. auriculata, the newly described S. herzogii de la Sota, and S. martynii Kopp—all of them occurring in Brazil. After that, Mitchell (1972) and Mitchel and Thomas (1972) formally named this group as the “Salvinia auriculata-complex” and described another taxon: S. molesta D.S. Mitch., the “Kariba weed,” which has become a invader species worldwide (see above). Although the type of S. molesta is from Zimbabwe, the origin of this species has always been attributed to Brazil.

Sehnem (1979) followed the conceptions of Sota (1962a, b, c), but ignored Mitchell’s (1972), listing only S. auriculata, S. herzogii, and S. minima to southern Brazil. Still in decades of 1970 and 1980, Forno and Harley (1979) and Forno (1983), searching for biological agents to control S. molesta in Australia, proposed a new taxonomy for the Salvinia auriculata-complex, providing new circumscriptions, new tools for identifications, and new geographical data for the Brazilian species of this complex. They considered S. auriculata, S. biloba, S. herzogii, and S. molesta as valid species occurring in Brazil.

Although working exclusively with Mesoamerican plants, Moran (1995) listed many Mesoamerican Salvinia from Brazil, such as Salvinia auriculata, S. minima, S. radula, and S. sprucei. In the same year, Sota (1995) presented new synonymies in Salvinia, considering his own S. herzogii a synonym of S. biloba, and S. molesta a synonym of the obscure name S. adnata Desv. Moran and Smith (1999) responded to Sota’s (1995) paper, presenting other interpretations to the name S. adnata and its type informations.

Pott and Pott (2000), in “Plantas Aquáticas do Pantanal,” listed Salvinia auriculata, S. biloba and S. minima to the Brazilian flooded forest biome Pantanal. Sota (2001) once again presented new circumscriptions to Salvinia species from the Americas, and he accounted eight species there: S. adnata, S. auriculata, S. biloba, S. martynii, S. minima, S. nuriana de la Sota, S. oblongifolia, and S. sprucei. According to Sota (2001), all of these occur in Brazil, and he once again emphasized the use of the name “S. adnata”, instead to “S. molesta.” Thus, Salino and Almeida (2010) and Prado et al. (2015), in the contemporary format of Flora of Brazil, recognized the same species and named as listed by Sota (2001). Among the eight species, five are occurring in southern and southeastern Brazil.

More recently, Miranda and Schwartsburd (2016), working on the regional flora of Viçosa (state of Minas Gerais, Brazil), rescued the name Salvinia molesta for Brazil and also pointed out new data on the genus in Brazil, citing new records of distribution and new characters with taxonomic value (including vegetative characters). Following up, Schwartsburd and Miranda (2017) formally wrote a proposal request to reject the name “Salvinia adnata”, since it might overthrown the name “S. molesta”, causing an undesired nomenclatural instability for a serious invasive plant around the world.

Taking in account the historical controversial taxonomy of the genus in Brazil and the lack of substantive geographical information, we here provide a taxonomic treatment for it in the southern and southeastern regions of this country.

2 Materials and methods

“Southern” and “southeastern” Brazil are, in fact, political divisions of Brazil. These two regions are formed by seven states: Minas Gerais, Espirito Santo, Rio de Janeiro, São Paulo, Paraná, Santa Catarina, and Rio Grande do Sul. The main phytogeographical domain of these states is the Atlantic Forest, but the Brazilian Savannah (Cerrado) is also notable, especially in the western areas of São Paulo and Minas Gerais. In addition, two steppe formations are also present there: the semiarid Caatinga in northern Minas Gerais and the Pampa in the southern most part of Brazil (in the state of Rio Grande do Sul) (IBGE 2012).

We analyzed materials from herbaria BHCB, BHZB, CAY, CESJ, CVRD, DIAM, ESAL, FLOR, FUEL, FURB, HAS, HB, HBR, HUFU, HURG, ICN, MBM, MBML, OUPR, PACA, R, RB, SJRP, SP, SPF, SPFR, UEC, UPCB, VIC, VIES. We also analyzed online images of types, from the Web sites of JSTOR (https://www.jstor.org/), Kew Gardens (http://www.kew.org/), Muséum National D’Histoire Naturelle (http://www.mnhn.fr/), Botanisher Garten und Botanisches Museum Berlin (https://www.bgbm.org/en/herbarium), Reflora (http://floradobrasil.jbrj.gov.br/reflora), plus images sent by the curator of herbarium LIL.

We performed field expeditions to at least one locality of each state. The collections are stored in herbarium VIC in spirit collection (70% ethanol) and a few also as exsiccates. We personally collected Salvinia auriculata var. major, S. biloba, S. herzogii, S. minima, S. molesta, and S. radula.

In the taxonomic treatment, morphological terms follow Forno and Harley (1979), Moran (1995), and Lellinger (2002), with the additions of Miranda and Schwartsburd (2016) for the hair systems and sorophore displays. The distribution maps were prepared using Diva-Gis (Hijmans et al. 2012), using political and hydrological layers. For the specimens without coordinates, we estimate them using Google Earth (www.google.com.br/intl/pt-BR/earth/).

3 Results and discussion

Species richness and distribution

– Based on morphology and geographical distribution, a new taxonomy of Salvinia from southern and southeastern Brazil is presented. This is somehow different from the last taxonomic treatments and lists of Brazilian Salvinia (e.g., Sota 2001; Salino and Almeida 2010; Prado et al. 2015; Miranda and Schwartsburd 2016). There, nine taxa occur, including a new variety and a new formally described hybrid: S. auriculata var. major C.V. Miranda & Schwartsb., S. biloba, S. cucullata, S. × delasotae C.V. Miranda & Schwartsb., S. herzogii, S. minima, S. molesta, S. oblongifolia, and S. radula.

The name “Salvinia auriculata” has been largely adopted to identify specimens from the area, both in the literature (e.g., Salino and Almeida 2010; Prado et al. 2015; Miranda and Schwartsburd 2016) and in herbaria labels. After studying specimens from the type locality (French Guiana) and elsewhere, we concluded S. auriculata s. str. (= S. auriculata var. auriculata) does not occur in southern and southeastern Brazil. The most similar taxon there is referred to as S. auriculata var. major, which is widespread in Brazil and possibly also in northeastern Argentina, Paraguay, and Uruguay (Fig. 1A).

Fig. 1

Distribution of Salvinia species in southern and southeastern Brazil (and some additional places). ASalvinia auriculata var. major; BSalvinia biloba; CSalvinia cucullata (black square) and Salvinia × delasotae (black triangle); DSalvinia herzogii

In southern and southeastern Brazil, five taxa belonging to the Salvinia auriculata-complex (i.e., taxa with fouet-like hair systems) occur: S. auriculata var. major, S. biloba, S. herzogii, S. molesta, and S. radula. A morphological comparison between them and S. auriculata var. auriculata is given in Table 1.

Table 1 Morphological comparison within the Salvinia auriculata-complex

Salvinia biloba occurs in the “Bacia do Prata,” in northeastern Argentina, Uruguay, Paraguay, Bolivia, and central to southern Brazil (Pott and Pott 2000; Arana 2016; present paper) (Fig. 1B). Salvinia herzogii occurs in Argentina and southern Brazil (present paper) (Fig. 1D). Salvinia molesta is native from southern Brazil (from the states of Paraná and Santa Catarina) and has been become invasive in many other regions, such as Australia, Botswana, Colombia, Cuba, Fiji, Guyana, India, Indonesia, Kenya, Malaysia, New Zealand, Papua New Guinea, South Africa, Trinidad, USA, and Zambia (Forno 1983; Oliver 1993; Moran 2004). In Brazil, apart from the states of Paraná and Santa Catarina, it is also present in Espírito Santo, Minas Gerais, Rio de Janeiro, Rio Grande do Sul, and São Paulo (Fig. 2B).

Fig. 2

Distribution of Salvinia species in southern and southeastern Brazil (and some additional places). ASalvinia minima; BSalvinia molesta; CSalvinia oblongifolia; DSalvinia radula

Salvinia minima is a widely distributed species, occurring from southern USA to central Argentina (Nauman 1993; Moran 1995; Mickel and Smith 2004; Arana 2016). Within Brazil, it is also widespread (Prado et al. 2015; present paper) (Fig. 2A). Salvinia radula is a commonly overlooked species, with only a few disjunct records. It is suggested to occur from Costa Rica southwards to Brazil and Paraguay (Moran 1995). In Brazil, the first records to the states of Maranhão, Pernambuco, Mato Grosso, Rio de Janeiro, and São Paulo are presented (Fig. 2D).

Salvinia oblongifolia is probably endemic to the northern (Pará) and northeastern states of Brazil (Alagoas, Paraíba, Bahia, Sergipe), slightly extending to the central-west (Goiás) and to the southeast (in the north regions of Minas Gerais) (Prado et al. 2015; present paper) (Fig. 2C).

Salvinia × delasotae, a putative hybrid between S. minima (widespread) and S. sprucei (restricted to northern South America and Central America), is probably native and common in areas of sympatry between the two parents (Sota and Cassa de Pazos 2001). Strangely, there is a collection from the city of Lorena, state of São Paulo, where S. minima occurs, but S. sprucei definitely not (Fig. 1C). Probably S. × delasotae was carried there as a cultivated specimen.

Another cultivated species found in southern Brazil is Salvinia cucullata, native from India (e.g., Chandra 2007). Researchers from Universidade Estadual do Oeste do Paraná cultivate this species to perform studies as bioadsorvent of synthetic dyes, such as Orange Acid 7 (Pelosi et al. 2014). Salvinia cucullata is a controlled cultivated species, with no records of escaping so far (Fig. 1C).

4 Morphology

Stems

– the stems in Salvinia are aquatic, horizontal, elongated, branched, and furnished with brown, catenate hairs. Form each node, two floating and one submerged leaves are born (Fig. 4B, K). The inter-nodes are detachable, and the nodes can originate new individuals through vegetative reproduction (cloning). These clonal unities have been named ramets (Room 1983). Salvinia has no roots.

Floating leaves

– they are green and responsible for the vegetative functions. They have short petioles, or they are absent. The laminae are divided into two equal lobes, with degree of incision varying among the species (Figs. 3B, F, J, M, 4C, G, O and 5B). Differently from the other ferns, the abaxial side of leaves is faced upwards (to atmosphere), whereas the adaxial side is faced the water (see development studies of Croxdale 1978, 1979, 1981). The abaxial surface has hair systems responsible for the floating of the plants. The adaxial surface bears catenate hairs.

Fig. 3

A–DSalvinia auriculata var. major: A Habit, B Floating frond, C Sorophore detail, D Hair system, fouet-like; E–HSalvinia biloba: E Habit, F Floating frond, G Sorophore detail, H Hair system, fouet-like; I–KSalvinia cucullata: I Habit, J Floating frond, K Hair system, simple; L–O. Salvinia herzogii: L Habit, M Floating frond, N Hair system, fouet-like, O Sorophore detail

Fig. 4

A–ESalvinia minima: A Habit, B Detail of a node, C Floating frond, D Hair system, ungulate, E Sorophore detail; F–ISalvinia molesta: F Habit, G Floating frond, H Sorophore detail, I Hair system, fouet-like; J–MSalvinia oblongifolia: J Habit, K Detail of a node, L Sorophore detail, M Hair system, spatulate; N–PSalvinia radula: N Habit, O Floating frond, P Hair system, with lonely catenate hairs

Fig. 5

Salvinia × delasotae: A Habit, B Floating frond with sparse hairs, C Detail of hairs of floating fronds margin, D Hair system

Veins

– the veins of the floating leaves are netted (anastomosing), forming aureoles without included veinlets. The aureoles can be either homogeneous in size or heterogeneous, and this is taxonomically important.

Hair systems

– this term was proposed by Miranda and Schwartsburd (2016) and consists of an association between a papilla and hairs above, or sometimes, only by hairs. Hair systems are found in the abaxial side of leaves, and they are a very conspicuous and unique feature of Salvinia. The papillae can be long, short, or rarely absent; they can also be filiform or cupuliform. The hairs above the papillae can be lonely, or there can be two, three, or four. They also can be united at their tips or loose from one another. These hairs have hydrophylic tips and super-hydrophobic bodies, being essential to the floating of the plants (Barthlott 2009, 2010). Hair systems with only one hair above are called simple (Fig. 3K); with two hairs united at the tips, spatulate (Fig. 4M); with three or four hairs united at the tips, fouet-like (Figs. 3D, G, N, 4I, P); and with four free hairs, ungulate (Fig. 4D). Salvinia radula have also lonely catenate hairs among the hair systems (Fig. 4P).

Submerged leaves

– they resemble roots, and it is believed they actually have similar functions of roots (Sculthore 1967). They are brown and highly branched, with almost no laminar tissue. Some leaves are responsible for the sexual reproduction of the plants, and thus, they get a hemi-dimorphic morphology. The trofophores can develop a conspicuous primary axis in some species. The trofophores are furnished with catenate hairs. In some species, the trofophores can get as much as 45 cm long.

Sorophores

– from the trofophores, the sorophores depart bearing the sori. The display of the sori in the sorophores is of great taxonomic value. They can be displayed as racemes (Fig. 3G), spikes (Figs. 3O, 4E, H), monocasia (Fig. 3C), or glomerula (Fig. 4L). The sori in spikes and racemes can vary in distance, according to each species.

Sori and indusia

– the sori is enclosed by indusia only. The term “sporocarp,” commonly applied to Salvinia sori, is found in other Salviniales, but not in Salvinia (Nagalingum et al. 2006). The shapes and sizes of the sori are variable: they can be globose or apiculate, sessile, or stalked. The indusia consist of two layers of cell, and thus, they are easily opened (Nagalingum et al. 2006). They are commonly furnished by catenate hairs.

Sporangia

– within the indusia, the sori can be formed by macrosporangia, microsporangia, or both. The macrosporangia are larger and yellowish, and they bear megaspores. The microsporangia are shorter, whitish, and they bear microspores. Salvinia molesta is believed to be alopentaploid, and it generally produces hollow sporangia.

5 Taxonomic treatment

Salvinia Ség., Pl. Veron. 3: 52. 1754. Type: Salvinia natans (L.) All. (= Marsilea natans L.).

Plants aquatic, floating, commonly mat-forming, heterosporous. Roots absent. Stems horizontal, branched, furnished with brown, catenate hairs, detachable in the inter-nodes; nodes bearing two floating leaves and one submerged leaf. Leaves dimorphic. Floating leaves green, orbicular, oblong-orbicular, or rounded, bilobed, proximally incised, distally incised or not; abaxial surface facing atmosphere, with hair systems (hairs + papillae) or rarely also with lonely hairs within the hairs systems; adaxial surface facing water, with conspicuous brown catenate hairs, or rarely glabrous; veins aureolate, with homogenous or heterogenous aureoles; hair systems fouet-like, spatulate, ungulate, or simple. Submerged leaves hemi-dimorphic, brown, highly dissected, root-like, to 45 cm long, with or without a developed primary axis, furnished with conspicuous brown catenate hairs; sorophores formed by one unbranched axis, equally branched axes, or unequally branched axes, forming racemes, spikes, monocasia, or glomerula; sori orbicular or apiculate, sessile, sub-sessile, or pedicelate, fully covered by indusia, furnished with catenate hairs, containing megasporangia and/or microsporangia; megasporangia larger than microsporangia; megaspores larger than microspores.

Key to Salvinia taxa from southern and southeastern Brazil:

Salvinia auriculata var. major C.V. Miranda & Schwartsb., var. nov. Type.

– BRAZIL. Minas Gerais: Viçosa, Universidade Federal de Viçosa, Lagoa do Recanto das Cigarras, 06 Jul 2017, C.V. Miranda and P.B. Schwartsburd 39 (holotype: SP!; isotypes: LIL!, NY!, P!, RB!, UC!, UPCB!, VIC!). Figure 3A–D.

Floating leaves with short petioles, 2–5 mm long; laminae sub-orbicular, rounded, and slightly incised at the apex, cordate at the base, 2–3 × 1.2–2.2 cm, abaxially with hairs systems, adaxially with catenate hairs; hairs systems fouet-like (papillae with four hairs jointed at the tips); papillae long; areolate veins homogeneous. Submerged leaves to 20 cm long, with short petioles, 1–3 mm long; trofophores highly dissected, without primary axis, with conspicuous, brownish, catenate hairs; sorophores displayed in scorpioid monocasia; sori large, globose, long-pedicelate.

Geographical distribution

– Brazil, in the states of Sergipe, Bahia, Mato Grosso do Sul, Minas Gerais, Espírito Santo, Rio de Janeiro, São Paulo, Paraná, and Rio Grande do Sul. Possibly also in Paraguay, Uruguay, and northeastern Argentina (no material seen).

Specimens examined

– BRAZIL. Minas Gerais: Viçosa, Campus da UFV, Represa do Belvedere, 27 Fev 1998, J. Alves de Oliveira s.n. (VIC-18642); ibid., lago da Silvicultura, 27 Mai 1998, I.C. Lovo s.n. (SP-298127); ibid., Lago atrás do Centro de Vivência, Campus UFV, 23 Jun 2005, E.A. Bontempo e Silva s.n. (VIC-30327); ibid., Campus da UFV, Represa do Belvedere, 27 Fev 1998, J. Alves de Oliveira s.n. (VIC-18642); ibid., Lagoa do Recanto das Cigarras, 03 Jun 2009, C. C. Rossi s.n. (32162); ibid., Lagoa das quatro pilastras, Campus UFV, 22 Jun 2205, E. A. Bontempo e Silva s.n. (VIC-30328); ibid., UFV, lado em frente a FUNARB, 01 Fev 1996, F.F. Coelho s.n. (VIC-15786); ibid., Lagoa da Dendrologia, Campus UFV, 25 Jul 2005, E.A. Bontempo e Silva s.n. (VIC-30326); ibid., campus da UFV, Recanto das Cigarras, 18 Abr 2013, P.B. Schwartsburd 2675 (VIC); ibid., Campus da UFV, lago da Silvicultura, 25 Mai 1996, I.V. Lovo s.n. (VIC-15944); Marliéria, Parque Florestal do Rio Doce, Lago D. Helvecio, 26 Jun 1983, I. Ikusima & J.G. Gentil s.n. (SP-192916); ibid., Parque Estadual do Rio Doce, 13 Fev 2000, S.L. Leite s.n. (BHCB-51577); Santa Rita do Itueto, 19°24′52″S, 41°22′45″W, 185 m, 27 Mai 2009, T.E. Almeida et al. 1958 (BHCB); Januária, Refúgio da Natureza, Rio Pandeiros, 15°40′32″S, 44°37′4″W, 468 m, 28 Set 2007, M.O. Pivari & P.L. Viana 590 (BHCB); Nova Lima, RPPN, Mata do Jambreiro, 19°58′41,9″S, 43°53′10,6″W, 06 Mai 2004, J.B. Figueiredo & A. Alves 435 (BHCB); Mathias Lobato, rio Suaçui, 18°33′22″S, 41°57′41″W, 24 Jan 2010, D.T. Souza 1053 (BHCB); Conceição das Alagoas, Usina Hidrelétrica de Volta Grande, 15 Dez 1998, A. Salino 4427 (BHCB). Espírito Santo: Cariacica, Reserva Biológica Duas Bocas, 20°16′22″S, 40°28′36″W, 14 Fev 2008, P.H. Labiak et al. 4606 (UPCB); ibid., Reserva Biológica de Duas Bocas, Represa Velha, 20°15′31″S, 40°29′51″W, 170 m, 11 Jun 2010, A. Salino et al. 14878 (BHCB); Guarapari, Setiba, Rodovia do Sol, ES 060, Lagoa do Milho, 20.6020°S, 40.4254°W, 18 Abr 1990, J.M.L. Gomes & O.J. Pereira 1003 (VIES); Linhares, Lagoa Jupuranã, 21 Ago 1987, G. Hatschbach & A.C. Cervi 51377 (MBM); ibid., Reserva Florestal de Linhares (CVRD), 19°12′ 33,9″S, 39°57′46,2″W, 30-60 m, 07 Fev 2007, T.E. Almeida et al. 648 (BHCB); Conceição da Barra, Reserva Biológica do Córrego Grande, 18°17′03,9″S, 39°48′18,3″W, 41 m, 12 Jun 2009, A. Salino et al. 14381 (BHCB). Rio de Janeiro: Macaé, estrada Nova Aroeira Km 103, Fazenda Arizona, 19 Nov 1982, J.R. Pirani et al. 151 (SP); Rio de Janeiro, Jardim Botânico, J.G. Kuhlman s.n. (RB-216835). São Paulo: Jundiaí, Serra do Japi, 23°14′S, 46°56′W, 996 m, 13 Nov 2009, J. Prado et al. 2074 (SP); Pinheiros, 05 Jul 1935, A. Gehrt s.n. (SP-33605); Tanabí, 20°38′S, 49°34′W, 600-700 m, Fazenda Rosa Branca, 13 Jun 1992, M.R. da Silva & C.E. Rodrigues Jr. 183 (SPF); ibid., Fazenda Rosa Branca, 13 Mai 1992, M.R. Pietrobom-Silva & C.E. Rodrigues Jr. 183 (SJRP); São José do Rio Preto, Represa Municipal, 11 Mar 1995, F.R. Nonato & M.R. Pietrobom-Silva 106 (SPF); Nova Granada, 11 Jun 1992, C.E. Rodrigues Jr. & M.R. Silva 50 (SJRP); São José do Rio Preto, Represa Municipal, 11 Mar 1995, F.R. Nonato & M.R. Pietrobom-Silva 106 (SJRP); ibid., Rio Turvo, Lagoa Braço Morto, 17 Mai 2005, R.B. Araújo s.n. (SJRP-29863). Paraná: Piraquara, Reservatório Piraquara II, 01 Fev 2012, S. C. Alves da Silva et al. 103 (UPBC); Pinhais, 18 Mai 1991, A.C. Cervi & A. Dunaiski 3209 (UPCB); Reservatório de Itaipu, 24°36′28,9″S, 54°16′33,4″W, 03 Jan 2006, E.A. Buzanello s.n. (BHCB-112765). Rio Grande do Sul: Torres, Parque Estadual de Itapeva, 09 Mai 2012, R.M. Senna 1457 (HAS); Santa Vitória do Palmar, 12 Jul 1980, D.M. Vital s.n. (SP-196546); Rio Grande, Bolacha, 27 Nov 1984, A. Cafruni s.n. (FURG-000864); Cidreira, Lagoa da Tapera, 10 Mar 2012, E. Valduga 336 (MBM); Capão da Canoa, Fazenda Pontal, 29°47′02″S, 50°08′51″W, 26 Ago 2001, F.P.F. Athayde & C.R. Lehn 1054 (SJRP).

Additional specimens examined

– BRAZIL. Sergipe: Nossa Senhora da Glória, 06 Out 1980, M.D. Souza 2838 (SPF); Frei Paulo, 26 Jul 1983, G. Viana 710 (SPF). Bahia: Camacã, Fazenda Serra Bonita, 15°23′30″S, 39°33′55″W, 835 m, 10 Jul 2005, F.B. Matos et al. 662 (UPCB); Ilhéus, Distrito de Rio do Braço, Fazenda Estrela da manhã, 80 m, 09 Dez 2014, A. Salino et al. 15992 (BHCB). Tocantins: Palmas, Fazenda São João, 10 Jan 2006, M. Sobral & J. Larocca 10433 (BHCB). Mato Grosso do Sul: Corumbá, Logradouro Margem esquerda do rio Paraguai, 17°59′39,7″S, 57°29′21″W, 100 m, 29 Jul 2001, E. Assis 248 (UPCB); ibid., Fazenda Santa Luzia, 09 Dez 1993, A.C. Cervi et al. 4244 (UPCB); ibid., 30 Nov 1979, A.T. Silva 244 (SP); ibid., 02 Dez 1979, A.T. Silva 253 (SP); Brasilândia, Fazenda Santa Maria, 21°43′S, 52°05′W, 25 Set 1996, M.R. Pietrobom-Silva 3559 (SP); Rio Paraguai, 29 Jul 1983, I. Ikusima s.n. (SP-192913); Ladário, Codrasa, 05 Jun 1999, E.L.M. Assis & I.H. Ishii 34 (BHCB). Nhecolândia, Fazenda Nhumirim, 03 Jul 1990, T.S.M. Grandi et al. 2762 (BHCB).

Salvinia auriculata var. major differs from S. auriculata var. auriculata mainly by the greater size of leaves, both the submerged and the floating ones. The floating leaves of fertile specimens from the type locality of S. auriculata (French Guiana) are 0.8–1.8 cm long, and the submeged leaves are 9 cm long. On the other hand, the fertile specimens from southern and southeastern Brazil have floating leaves measuring 2–3 cm long and submerged leaves to 20 cm long. These specimens are here named S. auriculata var. major and those S. auriculata var. auriculata. The size of leaves of fertile specimens was the basis for distinction of the two varieties (see other comparisons in Table 1).

Salvinia auriculata var. auriculata does not occur in southern and southeastern Brazil, having its limits of distribution in central and northeastern Brazil, where both varieties can co-occur. Future studies are needed to check the ploidy of these two taxa and whether var. major should be regarded as a distinct species.

Salvinia biloba Raddi, Pl. Bras. Nov. Gen. 1, t.1, Fig. 4A, B. 1825. Lectotype (designated by Sota 1995: 313).—BRAZIL. [Rio de Janeiro]: in fossis prope Rio de Janeiro praesertim in Mataporcos et Catumby, s.d., G. Raddi s.n. (PI; probable isolectotypes: BM, BOLO, FI, K). Figure 3E, H.

Floating leaves with short petioles, 1–9 mm long; laminae bilobed, with highly incised apex, to ½ of lamina length, with cordate base, 1.5–2.5 × 1.2–2.7 cm, abaxially with hair systems, adaxially with catenate hairs; hairs systems fouet-like (papillae with four hairs jointed at the tips); papillae long; areolate veins heterogeneous. Submerged leaves to 45 cm long, with short to long petioles, to 2 cm long; trofophores highly dissected, forming a primary axis, with conspicuous, brownish, catenate hairs; sorophores displayed in racemes; sori ovate-apiculate, long-pedicelate.

Geographical distribution

– Endemic to southern and southeastern Brazil, in the states of Espírito Santo, Minas Gerais, Rio de Janeiro, Paraná, Santa Catarina, and Rio Grande do Sul. Probably also in São Paulo (no material seen).

Specimens examined

– BRAZIL. Minas Gerais: Juiz de Fora, 16 Ago 1979, L. Krieger 2655 (CESJ); ibid., 16 Ago 1979, L. Krieger 4202 (BHCB). Ibid., 16 Ago 1979, R.C.A. Lafetá 31 (CESJ); Marliéria, Parque Estadual do Rio Doce, Lagoa do Aníbal, 19°47′3″S, 42°29′51″W, 261 m, 25 Set 2009, M. O. Pivari & A. Chavier 1382 (BHCB). Espírito Santo: Marilândia, 21 Set 2015, C.V. Miranda & P.B. Schwartsburd 14 (VIC); Nova Venécia, 18 Set 2015, C.V Miranda et al. 12 (VIC); ibid., APA Pedra do Elefante, 19 Set 2015, C.V. Miranda et al. 13 (VIC); ibid., APA Pedra do Elefante, Fazenda Santa Rita, 18°47′00″S, 40°26′00″W, 200 m, 15 Jan 2009, P.H. Labiak et al. 5139 (MBML); Guarapari, Setiba, 20.6020°S, 40.4254°W, 02 Ago 1990, L. Behar & G.M.F. Viégas 314 (VIES); ibid., Setiba, Rodovia do Sol, ES 060, Lagoa do Milho, 20.6020°S, 40.4254°W, 18 Abr 1990, J.M.L. Gomes & O.J. Pereira 1003 (VIES); ibid., Setiba, Restinga da Rodovia do Sol, Km 34, L. Behar & G.M.F. Viégas 307 (VIES); Linhares, Reserva do Rio Doce, 19°11.11′S, 39°54.22′W, 04 Dez 2003, C. M. Mynssen et al. 520 (RB), ibid., Lagoa Juparanã, 20 Abr 1979, I.W. Forno s.n. (RB-219037); ibid., Reserva Florestal de Linhares (CVRD), 19°12′33,9″S, 39°57′46,2″W, 30–60 m, 07 Fev 2007, T.E. Almeida et al. 647 (BHCB); ibid., Floresta Nacional de Goytacazes, 19°26′07″S, 40°04′26″W, 15 m, 14 Mai 2008, A. Salino et al. 13374 (BHCB); Rio Novo do Sul, Comunidade Couro dos Monos, Sítio do Aconchego, 20°50′27″S, 40°53′47″W, 15 Nov 2015, I.O. Moura et al. 67 (BHCB). Rio de Janeiro: Rio de Janeiro, 1873, Schwacke 963 (RB); ibid., Jardim Botânico, 1940, A.C. Brade 3083 (CESJ); ibid., 28 Mai 1937, Anonymous (RB-178298A); Cabo Frio, 09 Mar 1970, D.S. Mitchell 1235 (RB); ibid., 09 Mar 1970, D. Sucre & S.P. Santos 6455 (RB), São João da Barra, Reserva Particular do Patrimônio Natural Caruara, 29 Jul 2013, M.G. Santos & A.S. Portugal 2260 (RB); Campos, Jun 1918, A.J. de Sampaio 3100 (R); ibid., próximo a Lagoa de Cima, 19 Jul 1975, A.L. Peixoto 546 (RB); ibid., Fev 1981, I.W. Forno s.n. (RB-218995); ibid., Fev 1981, I.W. Forno s.n. (RB-218996); Macaé, Rio São Pedro, BR 101, Km 162, 17 Abr 1979, I.W. Forno s.n. (RB-219034); ibid., 17 Abr 1979, I.W. Forno s.n. (RB-219038); ibid., 17 Abr 1979, I.W. Forno s.n. (RB-219033); ibid., Rio Niterói, Km 121, 06 Ago 1978, I.W. Forno s.n. (RB-219007); ibid., Lagoa Feia, 10 Jun 1980, D. Araújo & N.C. Maciel s.n. (PACA-111739); Silva Jardim, Reserva Biológica de Poço das Antas, Estr. p/Juturnaiba, próx. a barragem, 05 Jan 1993, L. Sylvestre et al. 807 (RB); Itaboraí, Rio Guapimirim, 19 Mai 1977, D. Araújo 1687 (PACA). Paraná: Guaraqueçaba, 30 Mar 2013, P.B. Schwartsburd & M.P. Schwartsburd 2670 (VIC); ibid., 30 Mar 2013, P.B. Schwartsburd & M.P. Schwartsburd 2668 (VIC); ibid., 30 Mar 2013, P.B. Schwartsburd & M.P. Schwartsburd 2669 (VIC); ibid., 30 Mar 2013, P.B. Schwartsburd & M.P. Schwartsburd 2671 (VIC); Tunas do Paraná, Parque Estadual de Campinhos, 08 Mai 1998, O.S. Ribas et al. 2644 (MBM). Santa Catarina: Santa Rosa do Sul, 29°08′47,76″S, 49°40′46,17″W, 10 Mai 2011, A. Korte 6807 (FURB). Rio Grande do Sul: Palmares do Sul, 16 Jun 2013, R.M. Senna 1480 (HAS); ibid., 16 Jun 2013, R.M. Senna 1481 (HAS); Triunfo, 05 Set 2013, R.M. Senna & C. Mansan s.n. (HAS-49867); Sapiranga, 25 Out 2005, L. Neumann et al. s.n. (PACA-105355).

Salvinia biloba is similar to S. herzogii and S. molesta due to the bilobed floating leaves, but the apex incision in S. biloba is to ½ of lamina length, whereas in those other two species is only to 1/3. In addition, the sorophores in S. biloba are displayed in racemes (a primary axis with long-pedicelate sori), while they are displayed as spikes in S. herzogii and S. molesta. See also Table 1 for comparisons among the Salvinia auriculata-complex.

Salvinia cucullata Roxb. ex Bory & Bél., Voy. Indes Or. [Bélanger], Cryptogamie: 6. 1833. Type.—INDIA. Bengale, eaux de l’Hooglie, 1825–1829, M. Bélanger s.n. (G?). Figure 3I–K.

Floating leaves with short petioles, 0.5–1 mm long; laminae flabeliform, rounded ate the apex, truncate at the base, 0.5–1 × 1.1–1.5 cm, abaxially with hair systems, adaxially glabrous; hair systems simple (only one hair over the papillae); papillae short or absent; areolate veins heterogeneous. Submerged leaves to 3.5 cm long, with or without short petioles, 0.2–1 mm long; trofophores highly dissected, with stout laciniae, not forming a primary axis, with conspicous, brownish, catenate hairs; sorophores not seen; sori not seen.

Geographical distribution

– Native from India cultivated in the state of Paraná and commonly sold in Brazil.

Specimens examined

– BRAZIL. Paraná: Toledo, Centro de Pesquisa em Agricultura Ambiental CPAA/IAP, 16 Mar 2011, C.F. Olguin & M.T.F. Cornelius 12 (BHCB).

Salvinia cucullata differs from all other Salvinia in Brazil by the simple hair systems (i.e., with only one hair over each papilla). In the other species, the hair systems have two or more hairs. Adaxilly, S. cucullata is glabrous, whereas the other species are furnished with catenate hairs. In addition, the shape of laminae of the floating leaves is unique: rounded apex, truncate base.

Salvinia × delasotae C.V. Miranda & Schwartsb., hybr. nov. Type.

– BRAZIL. Amazonas: Manaus, 1976, L. Bacca s.n. (holotype: FURB!-00328). Figure 5A–D.

Floating leaves with short petioles, 1–2 mm long; laminae sub-flabeliform, rounded at the apex, cordate at the base, 0.3–0.6 × 0.3–0.5 cm, abaxially with hair systems present only in the distal 1/3 of the lamina, adaxially with catenate hairs; hairs systems ungulate (four free hairs over the papillae); papillae short to long; areolate veins heterogeneous. Submerged leaves to 2 cm long, with short petioles, 2.0–4.5 mm long; trofophores highly dissected, forming a primary axis, with conspicuous, brownish, catenate hairs; sorophores not seen; sori not seen.

Geographical distribution

– Uncertain, possibly everywhere the parents occur sympatrically, with definitive records from Trinidad and Brazil (in the states of Amazonas and São Paulo).

Putative parents

– Salvinia minima and S. sprucei.

Etimology

– The epithet honors Dr. Elías Ramón de la Sota (1932–2014), late pteridologist. Sota was one of the most important fern researches from Argentina and made many contributions in the study of Salvinia. This hybrid, in fact, was discovered by him.

Specimens examined

– BRAZIL. São Paulo: Lorena, 1940, A. Gehrt s.n. (SP-44413).

Salvinia sprucei differs from all other Brazilian species of Salvinia by the flabelliform laminae, prominent veins, and the hair systems restricted to the laminar margins. Salvinia sprucei occurs in northern South America (Amazon region) and Central America. In 2001, Sota and Cassa de Pazos (2001) reported a hybrid between S. sprucei and the widespread S. minima, from Trinidad and northern Brazil. The hybrid clearly presents intermediate morphology, such as the sub-flabeliform laminae and the hair systems restricted to the distal 1/3 of laminae. Although Sota and Cassa de Pazos (2001) reported the hybrid, they did not describe it as a new taxon. We here describe it, honoring Sota.

We analyzed two materials of this hybrid: one from northern Brazil, from a place near those specimens studied by Sota and Cassa de Pazos (2001), and another from São Paulo, which was probably cultivated there. Salvinia minima does occur in southeastern Brazil, but S. sprucei definitely not. New collections in the city of Lorena are needed to check if this hybrid has survived since 1940.

Salvinia herzogii de la Sota, Darwiniana 12: 514, Figs. 1, 2, 3. 1962. Type.—ARGENTINA. Santa Fé: Capital, Laguna Guadalupe, Mar 1961, M. Rodríguez s.n (holotype: LIL-001971, image!). Figure 3L–O.

Floating leaves with short petioles, 0.4–1.0 mm long; laminae bilobed, with highly incised apex, to 1/3 of lamina length, with cordate base, 1.5–2.5 × 2.7–3.8 cm, abaxially with hair systems, adaxially with catenate hairs; hairs systems fouet-like (papillae with four hairs jointed at the tips); papillae long; areolate veins heterogeneous. Submerged leaves to 10 cm long, with long petioles, 0.5–1 cm long; trofophores highly dissected, forming a primary axis, with conspicuous, brownish, catenate hairs; sorophores displayed in contracted spikes, with clustered sori; sori large and ovate (megasori), or short and ovate-apiculate (microsori).

Geographical distribution

– Argentina and Brazil, in the states of Rio de janeiro, São Paulo, Paraná, Santa Catarina, and Rio Grande do Sul.

Specimens examined

– BRAZIL. Rio de Janeiro: Rio de Janeiro, Jardim Zoológico, Jan 1941, J. Badini s.n. (OUPR-11931). São Paulo: São Paulo, Horto da Faculdade de Farmácia, 04 Dez 1951, W. Hoehne 3823 (SPF, SJRP, K-n.v., CESJ); ibid., Parque Previdência, 18 Mai 1987, V.C. Souza s.n. (SPF-61349); ibid., Parque Estadual das Fontes do Ipiranga, lago do hidrofitotério, 23 Fev 2006, J. Prado et al. 1630 (SP); ibid., 11 Mai 1975, L.C. Abreu 295 (SP); Nova Granada, 07 Dez 1990, R.G. Oliveira & S.R. Donelli 3 (SJRP); Birigui, Bairro São José, Estância Vanessa, 27 Out 1997, D. Silva 16 (SJRP); Barbosa, Fazenda Petrópolis, 27 Out 1995, “Adriana” et al. 17 (SJRP). Paraná: Curitiba, Parque Tingui, 05 Out 2016, C.V. Miranda 29 (VIC); General Carneiro, Fazenda Santa Cândida, Lago Curicaca, 01 Nov 2004, C. Bona et al. 205 (MBM). Santa Catarina: Florianópolis, UFSC, laguinho do Horto Botânico, 20 Mar 1991, D.B. Falkenberg 5453 (FLOR); São Bento do Sul, Horto Florestal do Samae, 25 Jan 2014, P. Schwirkowski 245 (FURB-11698). Rio Grande do Sul: Viamão, Estuário do Guaíba, Ilha das Pombas, 17 Jun 1975, A. Backes & I. Menegheti s.n. (HAS-1936); Gravataí, Banhado Grande, Faz. 4 Irmãos, 17 Mar 1983, T. Strehl 738 (HAS); Capivari, Dez 2001, B.E. Irgang s.n. (HAS-49834); Porto Alegre, Morro Santana, 05 Set 1980, J. Mendes s.n. (HAS-12755); ibid., Jardim Botânico, 27 Set 2013, R.M. Senna & A.P. Castro s.n. (HAS-49851); ibid., 27 Set 2016, C.V. Miranda 16 (VIC); ibid., Rio Guaíba, 06 Ago 1982, B. Irgang & J.E. Mariath s.n. (ICN-53244); Torres, Parque Estadual de Itapeva, 06 Ago 1972, B. Irgang et al. s. n. (ICN-27925); ibid., Parque da Guarita, 29 Mar 1991, D.B. Falkenberg 5454 (FLOR); S. Tapes, Arroio Adauto, 16 Mar 1986, G. Nhuch s.n. (ICN-69779); Guaíba, Fazenda São Maximiano, BR 116, Km 308, 17 Dez 2005, L.F. Lima 180 (ICN); ibid., BR 116, Km 32, s.d., E.R. de la Sota & N. Matzenbacher 6378 (ICN, PACA); Rio Grande, Campus Carreiros, Lago das Dunas, 15 Fev 2007, C.R.T. Trindade s.n. (HURG-004303); Terra de Areia, Rodovia Porta do Sol, junto à Lagoa Itapeva, 26°46′S, 50°04′W, 05 Jun 2001, F.P.F. Athayde et al. 951 (SJRP, PACA); Maquiné, Est. Exp. de Psicultura, Lagoa dos Quadros, 18 Dez 1999, A.Silva Jr s.n. (PACA-90871); Mostardas, BR 101, 22 Jun 2002, A.Silva Jr & P.L.F Gregório s.n. (PACA-105039); Pelotas, 17 Mar 1981, I.W. Forno s.n. (PACA-71422); Santa Maria, 01 Mai 1987, B. Irgang & A. Alvarez Filho s.n. (ICN-128091).

Additional specimens examined

– ARGENTINA. Corrientes: Ruta 12, desvio a Paso de la Patria, 19 Dez 1970, E.R. de la Sota et al. 6195 (RB).

Salvinia herzogii was described in 1962 by Sota (1962c). Thirty-three years later, the author himself synonymized it under S. biloba (Sota 1995). We found substantial morphological differences between these two species; thus, we would rather recognize S. herzogii as a valid species, distinct from S. biloba. See Table 1 for comparisons among these two species and also among the Salvinia auriculata-complex.

Salvinia minima Baker, J. Bot. 24: 98. 1886. Type

– BRAZIL. Santa Catarina: Itajahy, [1876], F. Müller 479 (holotype: K-000590864, image!; probable isotype: R! [as “144″]). Figure 4A–E.

Floating leaves with short petioles, 1–2 mm long; laminae orbicular, with rounded apex, with slightly cordate base, 6–13 × 5–10 mm, abaxially with hair systems, adaxially with catenate hairs; hair systems ungulate (four free hairs over the papillae); papillae long; areolate veins heterogeneous. Submerged leaves to 4.5 cm long, with short petioles, 1–2 mm long; trofophores highly dissected, not forming a primary axis, with conspicuous, brownish, catenate hairs; sorophores displayed in spikes; sori sub-sessile, ovate-apiculate.

Geographical distribution

– Widespread in the Americas, in the USA, Mexico, Guatemala, Honduras, Nicaragua, Costa Rica, Panama, Antilles, Bermuda, Colombia, Venezuela, Equador, Peru, Bolivia, Paraguay, Uruguay, Argentina, and Brazil (in the states of Amazonas, Mato Grosso do Sul, Pernambuco, Bahia, Minas Gerais, Espírito Santo, Rio de Janeiro, São Paulo, Paraná, Santa Catarina, and Rio Grande do Sul).

Specimens examined

– BRAZIL. Minas Gerais: Viçosa, Horto Botânico da UFV, 13 Out 2016, C.V. Miranda 30 (VIC); ibid., 08 Nov 2016, C.V. Miranda 31 (VIC); ibid., s.d., C.V. Miranda 36 (VIC); ibid., s.d., C.V. Miranda 37 (VIC); ibid., campus da UFV, lago do ECS, 13 Abr 2015, C.V. Miranda 10 (VIC); ibid., lago do ECS, 30 Jun 2014, P.B. Schwartsburd & T. Campos 3282 (VIC); Salto da Divisa, Fazenda Santana, 16°04′18,7″S, 40°03′17,2″W, 19 Fev 2003, A. Salino et al. 8274 (BHCB). Espírito Santo: Linhares, Reserva Natural da Vale, Trilha do Quaternário, 19°12′34″S, 39°57′45″W, 50 m, 18 Abr 2011, A. Salino et al. 15078 (BHCB); Castelo, Parque Estadual Mata das Flores, 20°37′05″S, 41°09′45″W, 120 m, 24 Jun 2008, A. Salino et al. 13488 (BHCB). Rio de Janeiro: Rio de Janeiro, Arboreto Jardim Botânico, 05 Nov 2003, F.R. Simões 105 (RB); ibid., 12 Mai 2003, F.R. Simões & C.M. Mynssen 33 (RB); ibid., 23 Ago 2004, F.S.C. Oliveira 14 (RB). São Paulo: Monte Castelo, Rio Feio, 21 Set 1978, I.W. Forno C71 (RB). Paraná: Carambeí, 24°59′22″S, 49°59′25″W, 21 Mar 2013, C. Michelon et al. 1851 (UPCB); Ponta Grossa, Represa Alagados, 11 Dez 2008, M.G. Lusa et al. 1 (UPCB); Piraquara, Reservatório Piraquara II, 01 Fev 2012, S. C. Alves da Silva et al. 101 (UPCB); ibid., Reservatório Piraquara I, 02 Fev 2012, S.C. Alves da Silva et al. 118 (UPCB); ibid., Reservatório Piraquara II, 05 Out 2011, C. Bona et al. 611 (UPCB); Curitiba, Parque Iguaçu, 28 Abr 1999, J. Cordeiro & A.M.S. Pereira 1531. Santa Catarina: Itajaí, Rio Itajaí-Mirim, Bairro Canhanduba, 01 Out 2016, C.V. Miranda & A. Reis 23 (VIC); ibid., Colônia Japonesa, 01 Out 2016, C.V. Miranda & A. Reis 26 (VIC). Rio Grande do Sul: Palmares do Sul, 18 Jun 2013, R.M. Senna 1478 (HAS); São Lourenço do Sul, Fazenda do Sobrado, 28 Set 2016, C.V. Miranda et al. 17 (VIC); Pelotas, BR 116, Km 230, 03 Jun 1978, I.W. Forno s.n. (RB-218991); ibid., Instituto Agronômico do Sul, 22 Out 1959, G.L. Brauner 134 (PACA); ibid., Canal São Gonçalo, 04 Dez 1996, B. Irgang & C. Gastal s.n. (HURG-001339); Estação Ecológica do Taim, Jul 1976, M.L. Porto s.n. (ICN-31421); ibid., Mar 1981, B. Irgang et al. s.n. (ICN-49941); São José do Norte, 28 Dez 1978, Waechter 1105 (ICN); Itaqui, Banhado São Donato, 30 Set 1983, R. Bueno 3235 (ICN); Rio Grande, Arroio Vieira, 26 Mai 1986, M.M.P. Tognella 337 (HURG); ibid., Cassino, 23 Dez 1997, M. Farias s.n. (HURG-001574); ibid., Campus Carreiros, FURG, 18 Out 2010, U.S. Jacobi s.n. (HURG-4485); ibid., Ilha do Leonídeo-Quinta, 26 Nov 1984, C. Cordazzo et al. s.n. (HURG-000908); ibid., Lagoa Verde, 20 Abr 1995, R. Castelão 542 (HURG-002504); Várzea de Gravataí, 10 Out 1962, A.R. Schultz 3109 (ICN).

Additional specimens examined

– BRAZIL. Amazonas: Rio Parauari, entre Laranjal e Vila Darcy, 12 Jul 1983, S.R. Hill 13112 (RB). Pernambuco: Betânia, Barragem do Juá, Riacho Salgueiro, 08°25′24.20″S, 38°02′46.80″W, 22 Out 2010, A.P. Fontana et al. 7156 (RB). Bahia: Itabuna, BR 415, Km 195, 22 Abr 1979, I.W. Forno s.n. (RB-219026); Pojucá (Perto de Catu), 25 Abr 1979, I.W. Forno s.n. (RB-219032). Mato Grosso do Sul: Corumbá, Logradouro Margem esquerda do Rio Paraguai, 17°59′29″S, 57°29′21″W, 100 m, 29 Jun 2001, E. Assis 249 (UPCB); ibid., “Baía da Medalha”, Passo do Lontra, 08 Mar 1997, F.F. Coelho s.n. (BHCB-37027).

Salvinia minima differs from the all other taxa of Salvinia from southern and southeastern Brazil by the ungulate hair systems (i.e., four free hairs over each pappilla). Exception is made for S. × delasotae, which is a hybrid involving S. minima and S. sprucei (see its comments for additional information).

Salvinia molesta DS. Mitch., Brit. Fern Gaz. 10(5): 251. 1972. Type

– RODESIA [ZIMBABWE]. Lake Kariba, Rizuruhuru River Inlet, 26 May 1972, D.S. Mitchell 1330 (holotype: SRGH; isotypes: B, image!, BM, BO, BOL, BR, image!, CAL, CHR, EA, GE, GH, K, image!, LISB, LP, M, MO, image!, NSW, P, image!, PDA, PRE, image!, RB!, US, WAG, image!, Z). Figure 4F–I.

Floating leaves with short petioles, 1–5 mm compr., laminae bilobed, highly incised at the apex, to 1/3 of lamina length, cordate at base, 1.7–2.5 × 3.5–4.5 cm, abaxially with hair systems, adaxially with catenate hairs; hairs systems fouet-like (papillae with four hairs jointed at the tips); papillae long; aureolate veins heterogeneous. Submerged leaves to 24 cm long, with short to long petioles, 0.2–1 cm long; trofophores highly dissected, not forming a primary axis, with conspicuous, brownish, catenate hairs; sorophores displayed in spikes, with segregate sori; soros sessile ovate-apiculate, hollow sporangia.

Geographical distribution

– Native from southern Brazil, exotic invasive in Australia, Botswana, Colombia, Cuba, Fiji, French Guiana, India, Indonesia, Kenya, Malaysia, New Zealand, Papua New Guinea, South Africa, southeastern Brazil, Trinidad, USA, Zambia. In Brazil, it is known from Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Santa Catarina, and Rio Grande do Sul.

Specimens examined

– BRAZIL. Minas Gerais: Viçosa, Campus da UFV, Horto Botânico, 06 Mar 2013, P.B. Schwartsburd & S.F. da Silva s.n. (VIC-47060); ibid., 06 Mar 2013, P.B. Schwartsburd & S.F. da Silva s.n. (VIC-44893); ibid., 02 Jun 2014, P.B. Schwartsburd & T. Campos 3266 (VIC). Rio de Janeiro: Rio de Janeiro, Jardim Botânico, 12 Jun 1940, J.G. Kuhlmann 6042 (RB); ibid., Jun 1940, J.G. Kuhlmann s.n. (RB-216833); ibid., 18 Jun 1940, J.G. Kuhlmann 6124 (RB); ibid., Lagoa Rodrigo de Freitas, 25 Abr 1923, Gurgel 30 (RB). São Paulo: Teodoro Sampaio, Região do Pontal do Paranapanema, Parque Estadual Morro do Diabo, Ilhota do Tolosa, 22°32′S, 52°11′W, 200 m, 18 Jan 1995, M.R. Pietrobom-Silva 1633 (SJRP). Paraná: Piraquara, 11 Mai 1992, A. Dunaiski Jr. 234 (FUEL); ibid., Fazenda do Sr. Pedro Jeicy, BR 277, Km 12, 18 Abr 1978, I.W. Forno s.n. (RB-219052); ibid., 05 Fev 1980, I.W. Forno s.n. (RB-219000); Contenda, 25 Fev 1980, I.W. Forno s.n. (RB-219058); ibid., 25 Fev 1980, I.W. Forno s.n. (RB-219046); Praia de Leste, Rio Guaraguaçu, Km 15, 31 Mar 1978, I.W. Forno s.n. (RB-219051); ibid., Km 15-17, 31 Mai 1978, I.W. Forno s.n. (RB-221259); Curitiba, Est. Paranaguá, 04 Fev 1981, I.W. Forno s.n. (RB-219044); Roseira, 20 km de Curitiba, 29 Out 1981, Brücker & Lüönd s.n. (MBM-101417). Santa Catarina: Rio do Sul, BR 470, Km 136, 01 Jun 1978, I.W. Forno s.n. (PACA-71414); Blumenau, Rua Gustavo Zimmerman, 26°47′55″S, 49°05′03″W, 23 Fev 2010, K. Kemmelmeier s.n. (FURB-19121); ibid., 26°41′45.00″S, 49°03′41.00″W, 05 Mai 2013, L.A. Funez & K. Kemmelmeier 2141 (FURB); Imbituba, Rio Araçatuba, 14 Mar 1978, G. Hatschbach 41116 (MBM); Itapocu, Rio Itapocu, 14 Mar 1978, G. Hatschbach 41113 (PACA); Morro da Fumaça, em lagoa do lado de Olaria, 23°38′34″S, 49°11′16″W, 22 Out 2014, J.P.R. Faria & L. Funez 647 (FLOR); Florianópolis, Lagoa Pequena, Campeche, 27°39′18″S, 48°28′36″W, 01 Fev 2014, J.P.R. Ferreira & R. Trevisan 602 (FLOR); ibid., Lagoa Pequena, Campeche, 03 Out 2016, C.V. Miranda 28 (VIC); Joinville, Rio Pirabeiraba, BR 101, Km 19, 26 Mar 1978, I.W. Forno s.n. (RB-219049); ibid., s.d., I.W. Forno 28 (RB-221257); ibid., BR 101, Km 63, 14 Mar 1978, I.W. Forno s.n. (RB-219048); Araçatuba, BR 101, Km 272, 17 Set 1978, I.W. Forno 70 (RB); ibid., Fev 1980, I.W. Forno s.n. (RB-219057); ibid., 19 Mar 1981, I.W. Forno s.n. (RB-218993); ibid., 10 Out 1978, I.W. Forno 15 (RB); ibid., 25 Jan 1980, I.W. Forno s.n. (RB-218999); ibid., 25 Jan 1980, I.W. Forno s.n. (RB-218997); Mafra, Rio São Lourenço, 11 Mai 1978, I.W. Forno s.n. (RB-219053); Tubarão, BR 101, Km 343, Fev 1980, I.W. Forno s.n. (RB-219056); ibid., 10 Out 1978, I.W. Forno s.n. (RB-219045); ibid., 25 Jan 1980, I.W. Forno s.n. (RB-218998); ibid., Rio Araçatuba, BR 101, Km 272, 10 Out 1978, I.W. Forno s.n. (RB-219047). Rio Grande do Sul: Rio Grande, Arroio Bolacha, 07 Abr 1986, M. Farias s.n. (FURG-000215); Santo Antônio da Patrulha, 29°56′58″S, 50°32′27″W, 27 Abr 2014, F. Gonzatti 1156 (FLOR); Atlântida Sul, 13 Abr 1995, T.H. Ribeiro s.n. (ICN-107049); Pelotas, Bairro Baronesa, Jan 2004, A.R. Gonçalves s.n. (ICN-130213); Guaíba, 16 Mar 1978, I.W. Forno s.n. (RB-219055); ibid., 17 Mar 1978, I.W. Forno s.n. (RB-219050); Porto Alegre, Parque da Redenção, laguinho perto do Buda, 29 Set 2016, C.V. Miranda 20 (VIC).

Additional specimens examined

– ARGENTINA. Corrientes: Dep. Mburucuyá, 04 Jan 2006, E.I. Meza Torres et al. 310 (RB); ibid., Laguna Ibera, 16 Abr 1980, I.W. Forno s.n. (RB-219365).

Salvinia molesta is a highly aggressive invasive species with high rates of vegetative reproduction, and it is tolerant to several types of weather. Apparently, its alopentaploid origin gave it the vigor of an invasive species.

Salvinia biloba and S. herzogii are the most similar species, and at least one of them may have played part on the origin of S. molesta. For differentiation among these three species, and also among the remaining taxa of the Salvinia auriculata-complex, see Table 1.

Salvinia oblongifolia Martius, Icon. Pl. Crypt. 128, t. 75, Fig. 2, T. 76. 1834. Type

– BRAZIL. Pará: prope urbem S. Maria de Belem, et ad Tocantins fluvium passim, s.d., C.F.P. Martius s.n. (BR?, M?). Figure 4J–M.

Floating leaves unequal in each node (one bigger), with short petioles, 4–6 mm long; laminae oblong, ca. 3 times longer than large, slightly incised at the apex, slightly cordate at the base, 2.0–4.5 × 1.0–2.0 cm, abaxially with hair systems, adaxially with catenate hairs and a conspicuous keel; hair systems spatulate; papillae short and cupulliform; aureolate veins nearly homogeneous. Submerged leaves to 10 cm long, somehow attached to the shorter floating leaf, with short to long petioles, 0.4–1 cm long; trofophores highly dissected, forming a primary axis, with conspicuous, brownish, catenate hairs; sorophore displayed in glomerulae; sori large, spheroidal.

Geographical distribution

– Brazil, in the states of Pará, Goiás, Alagoas, Sergipe, Paraíba, Bahia, and northern Minas Gerais.

Specimens examined

– BRAZIL. Minas Gerais: Jaíba, Distrito Irrigação, 18 Jul 1995, E.T. Neto 1880 (MBM, BHCB); Januária, Distrito de Tejuco, Rio Pandeiros, 15°39′59.5″S, 44°37′58.2″W, 05 May 2002, A. Salino 8012 (BHCB).

Additional specimens examined

– BRAZIL. Bahia: Angüera, Lagoa 5, 12°11′S, 39°09′W, 03 Nov 1996, E. Melo et al. 1818 (MBM, HUEFS- n.v.); Castro Alves, 12°43′14.9″S, 39°21′34.1″W, 21 Mar 2010, L.Y.S. Aona et al. 1198B (FURB, HERB- n.v.); Sussuarana, Fazenda Escura, 14°13′12″S, 41°06′15″W, 714 m, 18 Sep 2015, L.Y.S. Aona et al. 4343 (FURB, HURB- n.v.); Muritiba, Pedra do Cavalo, Rio Paraguaçu, 12°35′84.2″S, 39°00′24.2″W, 336 m, 24 Jul 2012, L.Y.S. Aona et al. 1519 (FURB).

Salvinia oblongifolia is easily characterized by the oblong laminae, ca. 3 times longer than wide, by the conspicuous keels, and the spatulate hairs systems with two jointed hairs over each cupulliform papilla.

Salvinia radula Baker, J. Bot. 24: 98. 1886. Lectotype (designated by Weatherby 1937: 101)

– GUYANA. Locality unknown, s.d., C.S. Parker s.n. (K-000229470, image!). Figure 4N–P.

Floating leaves with short petioles, 1–3 mm long; laminae sub-orbicular, rounded at the apex, cordate at the base, 0.7–1.5 × 0.5–1.2 cm, abaxially with hair systems and free catenate hairs among them, adaxially with catenate hairs; hair systems fouet-like (papillae with four hairs jointed at the tips); papillae short or absent; aureolate veins homogeneous. Submerged leaves to 3.5 cm long, with or without short petioles, to 1 mm long; trofophores highly dissected, not forming a primary axis, with conspicuous, brownish, catenate hairs; sorophores not seen.

Geographical distribution

– From Costa Rica southwards to Brazil and Paraguay, but with only a few records. In Brazil, it is known from the states of Maranhão, Pernambuco, Mato Grosso, Rio de Janeiro, and São Paulo.

Specimens examined

– BRAZIL. Rio de Janeiro: Rio de Janeiro, Jardim Botânico, 02 Abr 2015, L. Mautone s.n. (RB-622277); ibid., Arboreto Jardim Botânico, 23 Jun 2003, F.R. Simões 48 (RB); ibid., 05 Nov 2003, F.R. Simões 106 (RB); ibid., 09 Out 2003, F.R. Simões 100 (RB); ibid., 20 Fev 2017, C.V. Miranda & N.S. Braga 32 (VIC). São Paulo: Planalto, Fragmento G-03, 21°00′S, 49°59′W, 440 m, 29 Nov 2007, J. Prado et al. 1738 (SP, TAIF-n.v.); São Paulo, Reserva Biológica, Parque Estadual das Fontes do Ipiranga, 07 Mai 1974, L. Camargo de Abreu 138 (SP); Piraju, 16 Mai 1996, A. Rapini et al. 159 (SP); São José do Rio Preto, Instituto Florestal de São José do Rio Preto, Km 443, 29 Out 1998, A.L.S. Castro 17 (SJRP); ibid., 20°48′S, 49°23′W, 29 Oct 1998, T.C. Mariguela et al. 7 (SJRP).

Additional specimens examined

– BRAZIL. Maranhão: Grajaú, s.d., G. Eiten & L. Eiten 10234 (SP). Pernambuco: Betânia, Barragem do Juá, Riacho Salgueiro, 08°25′24.20″S, 38°02′46.80″W, 22 Out 2010, A.P. Fontana et al. 7157 (RB). Mato Grosso: Santa Cruz do Xingu, Parque Estadual do Xingu, 09°50′57″S, 52°46′45″W, 252 m, 08 Mar 2011, D.C. Zappi et al. 3202 (RB); Cáceres, 16°05′S, 57°40′W, 1 Nov 1998, D.F. Vieira 14 (SJRP).

Salvinia radula was considered a synonym of S. auriculata by some authors (Herzog 1935; Sota 1982). On the other hand, Weatherby (1937) and Moran (1995) showed significant morphological differences between these two species. We here follow this last circumscription. Salvinia radula is unique in having free catenate hairs among the hair systems, as well as short to absent papillae. See Table 1 for other comparisons among the Salvinia auriculata-complex.

6 Doubtfull names

Salvinia auriculata var. olfersiana Klotzsch ex Baker, J. Bot. 24: 99. 1886. Salvinia orlfersiana (Klotzsch ex Baker) Britt., Fl. Bermuda 428. 1918. Syntypes

– FRENCH GUIANA. Locality unknown, s.d., M. Poiteau s.n. (P-00636762, image!). FRENCH GUIANA. Mana, 1857, P. Sagot 745 (P-00636757, image!, P-00636758, image!, P-00636759, image!, P-00636760, image!, P-00636761, image!). BRAZIL. Locality unknown [probably southern Brazil], s.d., Olfers s.n. (K-000590863, image!, S-059088, image!). PARAGUAY. l’Assomption, Dec 1876, B. Balansa 1123 (K-000590856, image!, P-00636751, image!, P-00636752, image!).

We refrain from choosing a lectotype by only looking at images. Apparently, the syntypes correspond to several taxa: Salvinia auriculata var. auriculata (Poiteau and Sagot 745), and S. herzogii or S. minima (Balansa 1123 and Olfers).

Salvinia martynii Kopp, Kulturbeding. System. Merkm. Salviniaart. 42, Fig. 24, t. 4. 1936. Lectotype (designated by Sota and Cassa de Pazos 1992: 316)

– GUYANA. In gardens, Feb 1943, Martyn s.n. (B-200090349, image!).

According to Sota and Cassa de Pázos (1992), Salvinia martynii is very similar to S. auriculata, differing only by histological characteristics. Besides, it is not known fertile specimens of S. martynii. It has been cited for the Brazilian states of Mato Grosso and Maranhão (Sota 1962a, b, c; Sota and Cassa de Pázos 1992; Prado et al. 2015).

Salvinia rotundifolia Willd., Sp. Pl., ed. 4 [Willdenow] 5: 537. 1810. Lectotype (designated by Morton 1967: 75)

– BRAZIL. Locality unknown, s.d., J. C. von Hoffmannsegg s.n. (B-Willd. [20250], image!; isolectotypes: HAL-137811, image!, LE-00000276, image!).

According to the protologue, Salvinia rotundifolia is similar to S. biloba, especially by the sorophores in racemes. On the other hand, the type is similar to S. auriculata var. auriculata, especially on leaf shape. Some authors considered it a synonym of S. auriculata (Baker 1886; Christensen 1906), while others an earlier name to S. minima (Herzog 1935; Weatherby 1937; Sota 1962a, b, c). Morton (1967) noted the type has fouet-like hair systems, thus belonging to the Salvinia auriculata-complex. Morton (1967) and Moran (1995) then considered it a synonym of S. auriculata. Only by seeing images of the type, we cannot address which other name would match with S. rotundifolia, or if it is even a species different from the others.

Besides, the type locality information is too vague (“Brazil”). The Count of Hoffmannsegg received many Brazilian specimens from his collaborators, as far as from Amazonas, Ceará, Pernambuco, Bahia, and Rio de Janeiro (Straube 2011).

7 Excluded Names

Salvinia adnata Desv., Mém. Soc. Linn. Paris 6 (2): 177. 1827. Lectotype (designated by Sota 1995: 313)

– BOURBON ISLAND [REUNION ISLAND]. s.d., ex Herb. Lavallée (P-00636764, image!)

Schwartsburd and Miranda (2017) wrote a proposal request to reject the name “Salvinia adnata,” since it might overthrown the name “S. molesta,” causing an undesired nomenclatural instability for a serious invasive plant around the world. See Introduction for further information.

8 Species excluded from the area

Salvinia auriculata Aubl. var. auriculata, Hist. Pl. Guiane 2: 969, t. 367. 1775. Type

– FRENCH GUIANA. s.d., Aublet s.n. (P?).

See second paragraph of Results and Discussion and Table 1.

Salvinia hispida Kunth, Nov. Gen. Sp. [H. B. K.] 1. 44. 1815. Type

– CUBA. s.d., Humboldt & Bonpland s.n. (B, P-00636763, image!) = S. auriculata var. auriculata.