Peperomia Ruiz & Pavón (1794: 8)

Mai, Patricia, Rossado, Andrés, Bonifacino, José M. & Waechter, Jorge L., 2016, Taxonomic revision of Peperomia (Piperaceae) from Uruguay, Phytotaxa 244 (2), pp. 125-144 : 128-142

Peperomia Ruiz & Pavón (1794: 8)

Herbs, epiphytic, epipetric or terrestrial. Stems erect, decumbent, repent or pendant, filiform to succulent. Leaves alternate, opposite or verticillate, without stipules; leaf blade glabrous or pubescent, with translucent dots. Inflorescences terminal or axillary, spikes or racemes. Flowers bisexual, subtended by peltate bracts, perianth absent; stamens 2, attached to the base of floral bract, filaments short, anthers unilocular, dehiscence longitudinal, extrorse; ovary sessile or inconspicuous pedicellated. Fruits berries or drupes, sometimes with pseudocupule (differential growth of a brown cuticle, which covers the fruit from the base to the middle), often partly immersed in pits of the rachis.

Identification key of Peperomia species occurring in Uruguay

1. Leaves alternate, membranous (live); fruits with hispid trichomes..............................................................................3. P. hispidula

1´. Leaves opposite or verticillate, coriaceous to succulent (live); fruits glabrous.................................................................................2

2. Leaf margins glabrous, mostly revolute; veins on abaxial surface markedly prominent and glabrous.............................................3

2´. Leaf margins with trichomes, flat (live); veins on abaxial surface not prominent, or if prominent then with trichomes..................4

3. Stems repent to pendant, cylindrical or slightly angular (live); leaf blades longer than 2.6 cm ..............................5. P. pereskiifolia

3´. Stems erect to decumbent, markedly angular (live); leaf blades up to 2.6 cm long................................................. 8. P. trineuroides

4. Spikes two or more together; flowers loosely arranged; fruits without pseudocupule; leaf baldes mostly more than 2 cm long.....5

4´. Spikes solitary; flowers densely arranged; fruits with pseudocupule; leaf blades up to 1.7 cm long................................................6

5. Leaves verticillate; apical leaf blades length-width ratio> 2.3................................................................................2. P. comarapana

5´. Leaves mostly opposite; apical leaf blades length-width ratio <2.2 .......................................................................... 4. P. increscens

6. Rachis of developed spikes with trichomes; margin of floral bracts entire; leaf adaxial surface with whitish or light green lines (live) ........................................................................................................................................................................... 7. P. tetraphylla

6´. Rachis of developed spikes glabrous; margin of floral bracts irregular; leaf adaxial surface evenly colored (live).........................7

7. Stems erect or decumbent; leaf blades obovate to orbicular; rachis of developed spikes up to 1.8 cm long, verruculose.................. .................................................................................................................................................................................... 1. P. catharinae

7´. Stems repent or pendant; leaf blades rhombic or rhombic-elliptic; rachis of developed spikes more than 2.5 cm long, smooth .........................................................................................................................................................................................6. P. psilostachya

1. Peperomia catharinae Miquel (1843: 127) . Type:— BRAZIL. Santa Catarina: Ste Catherine, 1832, Gaudichaud- Beaupré 282 (holotype G-00438558 on-line image!, isotypes [G-DC] G-00207738 on-line image!, P-00463555 on-line image!, P-00463556 on-line image!, U not seen) ( Fig. 1 )

= Peperomia herteri Trelease (1941: 66) . Type:— URUGUAY. Treinta y Tres: In Montevideo culta, e Treinta y Tres, Herter 15 (holotype ILL, missing). Neotype (designated here):— URUGUAY. Cerro Largo: Sierra de Ríos , crypt. mont., saxicola loc. umbr., 100–150 m, February 1937, Herter s.n. in Herb. Herter 98388 (ILL-00009103 on-line image!, isoneotype G-00406436 on-line image!).

= Peperomia uruguayana Trelease (1941: 66) . Type:— URUGUAY. Treinta y Tres: hab. Cebollati. Epiphyte, 18 March 1902, Berro 2883 (holotype [G-DC] G-00327181 image!, isotype MVFA-0000051!).

Herbs, epiphytic and sometimes epipetric. Stems erect, occasionally decumbent, branching dichotomously, cylindrical (live), puberulous, adventitious roots only present in the base. Leaves 3(4) verticillate or occasionally opposite basally; petiole 0.8–2 mm long, puberulous; leaf blade 0.7–1 × 0.5–0.7 cm, succulent, obovate to orbicular, sometimes ellipticobovate, 3–veined, veins obscure or main vein notorious (live) but not prominent, abaxial and adaxial surface glabrous or with scarce trichomes, margin with trichomes, base cuneate to rounded, apex rounded. Spikes 1.6–4 cm long, solitary, terminal, straight; peduncle 1.1–2.5 cm long, pubescent; rachis 0.5–1.8 cm long, glabrous, verruculose, densely flowered; bracts ca. 0.5 mm diam., circular, margin irregular. Fruits ca. 0.75 mm long, ovoid, sessile, located in pits of the rachis, verruculose, glabrous, pseudocupule viscose on the basal third.

Subgenus:— This species belongs to the subgenus Pseudocupula ( Frenzke et al. 2015) .

Distribution and habitat:— Argentina, Brazil and Uruguay. In the Southern Cone occurs from northeastern to central-eastern Argentina (Buenos Aires, Entre Ríos, Misiones, Santa Fe), southern Brazil (Paraná, Rio Grande Do Sul, Santa Catarina) and eastern and southeastern Uruguay (Cerro Largo, Lavalleja, Maldonado, Rivera, Rocha, Treinta y Tres). Maldonado and Rocha departments represent the southern limit of distribution for this species; Cerro Pan de Azúcar (Maldonado) is the southernmost locality where it was registered ( Fig. 2A ). In Argentina Peperomia catharinae reaches the Paraná River Delta, along with P. comarapana , establishing the southern limit of Peperomia in this country ( Burkart 1945, 1951). In Uruguay P. catharinae is the most widely distributed species of the genus, along with P. tetraphylla . It occurs in xeric hillside, moist hillside, hydrophilous, and riverside forests. The species grows on rocks but mainly on trunks and branches of various tree species.

Phenology:— Developing spikes were observed from February, flower anthesis from April to November and mature fruits from September. The species shows a wide flowering period and the spikes with mature fruits or without fruits (from the former period) remain on the plant for a long time, and thus co-occur with new spikes in different flowering stages.

Conservation assessment:— This species was categorized in the AOO analysis as Least Concern (LC) for Uruguay. It is a common species with high frequency throughout its distribution range in the country. It occurs in two protected areas ‘Paisaje Protegido Quebrada de los Cuervos’ and ‘Parque Nacional San Miguel’.

Distinctive and field characters:— In Uruguay Peperomia catharinae is characterized by its epiphytic or epipetric habit, small size, and obovate to orbicular leaf blade. Moreover it is the only species of Peperomia in Uruguay with both verticillate leaves and a rachis less than 1.8 cm long. In shade and wet places the leaves are green to dark-green and thin, while in sunny places the leaves are light green-yellow or sometimes reddish, and are more thickened. Mature fruits are brown and sticky.

Background in Uruguay:— Trelease (1941) and Trelease & Herter (1952) mentioned Peperomia herteri and P. uruguayana for Uruguay, and later Marchesi (1968) and Yuncker (1974) cited the presence of P. catharinae .

Taxonomic observation:— The holotype of Peperomia herteri was not found in ILL (David Seigler com. pers.), where the Herb. Trel. is located, besides the protologue did not include an illustration. In the species protologue, under a note of the editor the additional herbarium specimen Herb. Hert. 94032 is indicated, but was also not found. Nevertheless after a thorough review of the diagnosis of P. herteri we include this name as a synonym of P. catharinae because the diagnosis fits the type of the latter. Additionally, we analyzed some specimens that have typical characteristics of P. catharinae (Herb. Hert. 90961 (ILL, LAU, Z 3) and 98388 (G, ILL)), specimens deposited at ILL were both identified as P. herteri by Trelease. Surprisingly, they were included by Trelease (1941) as paratypes of P. tacuariana Trel. , and in the present work are discarded as type material of that taxon. Based on these circumstances we decided to designate as neotype of P. herteri the specimen Herb. Hert. 98388 (ILL), as it fits very well the diagnosis and has the seal and handwriting of Trelease identifying the specimen as belonging to P. herteri .

Specimens examined:— URUGUAY. Cerro Largo: Aº de la Mina, 31º55’9.3’’S, 54º6’27.7’’W, 24 February 2013, Mai & Rossado 241 (MVJB) ; Aº Las Cañas camino a Sierra de Ríos , 32º18’6’’S, 53º52’58’’W, 17 April 1999, Brussa & Grela s.n. (MVFA 29106) ; Sierra de Ríos , 32º14’47.4’’S, 53º46’59.6’’W, 21 September 2013, Mai et al. 337 (MVJB). Lavalleja: Aº Gutiérrez y Ruta 8, 33º31’30.1’’S, 54º34’6.5’’W, 20 February 2013, Mai et al. 176 (MVJB) ;

3 Specimens hosted at LAU and Z are identified as Peperomia exauctorata , this name is an unpublished designation, as it was mentioned by Tralease (1941).

Río Cebollatí, cerca Ruta 8, 33º49’47.57’’S, 54º47’24.46’’W, 24 November 2012, Mai et al. 112 (MVJB). Maldonado: Cerro Pan de Azúcar , [34º48’35’’S, 55º15’26’’W], 27 June 1965, Marchesi 1380 (MVFA) ; Gruta de Salamanca, 34º4’45.35’’S, 54º36’30.86’’W, 26 November 2012, Mai & Rossado 125 (MVJB). Rivera: Cuchilla del Yaguarí , 31º43’33’’S, 55º15’59’’W, en el camino 9 km al N de Ruta 44, 17 May 2014, Toranza & Haretche s.n. (MVJB 29167). Rocha: Aº Chafalote, 34º16’49’’S, 54º7’25’’W, 24 September 2012, Mai et al. 51 (MVJB) ; Cº del Águila , 34º17’21’’S, 54º7’52’’W, 24 September 2012, Mai et al. 58 (MVJB) ; Cº de la Lechiguana, 34º6’43’’S, 53º51’20’’W, 23 September 2012, Mai et al. 33 (MVJB); Laguna de Castillos , 34º16’19’’S, 53º59’23’’W, 23 September 2012, Mai et al. 41 (MVJB) ; Parque Nacional San Miguel , 33º42’48’’S, 53º34’40’’W, 13 October 2012, Rossado 5 (MVJB) ; Sarandí del Consejo, Laguna Negra, [34°16’0.01”S, 53°59’39”W], 9 June 1995, Bayce et al. s.n. (MVFA 26428). Treinta y Tres: Quebrada de los Cuervos , [32º55’30’’S, 54º27’42’’W], 09 April 1936, Legrand 703 (MVM) .

Additional specimens examined:— ARGENTINA. Misiones: General Belgrano, Bdo. De Irigoyen , 26º16’4.1’’S, 53º39’24.5’’W, 820 m, 14 January 2011, Keller & Franco 9449 (CTES) ; Igauazú, Paraje Aguaray , 7 September 2001, Keller et al. 1232 (CTES) ; Predio Guaraní , límite del predio con IPS, 26º54’59’’S, 54º12’18’’W, 24 August 1996, Tressens et al. 5656 (CTES) ; Predio Guaraní, Aº Paraíso , 26º54’59’’S, 54º12’18’’W, 16 September 1998, Tressens et al. 6052 (CTES) ; San Pedro, Aldea aborigen Teko´a Yma , 25 March 2004, Keller & Benitez 2734 (CTES) . BRAZIL. Rio Grande do Sul: Torres, [29º21’4’’S, 49º44’55’’W], 17 January 1984, Krapovickas & Cristóbal 39357 (CTES). Santa Catarina: Araranguá , Morro dos Conventos, [28º56’41’’S, 49º22’25’’W], 26 November 1980, Krapovickas & Vanni 36942 (CTES) .

2. Peperomia comarapana A. C. P. de Candolle (1915: 8) . Type:— BOLIVIA. Santa Cruz: Comarapa,An Erdabbrüchen in der Felssteppe bei Comarapa, 1900 m, April 1911, Herzog 1903 (holotype [G-DC] G-00319224 on-line image!, isotypes L-1542134 image!, [S] S-R-4157on-line image!, Z-000019273 on-line image!) ( Fig. 3 )

Herbs, terrestrial or accidentally epiphytic. Stems erect and stoloniferous, cylindrical (live), densely pubescent, adventitious roots only present in the base. Leaves 3–5(6) verticillate, occasionally opposite basally; petiole 1–8 mm long, pubescent; leaf blade (1) 2–4 × 0.6–1.2 cm, succulent or slightly succulent, elliptic to obovate, 3–veined, veins visible and not or slightly prominent abaxially, branched apically, abaxial and adaxial surface pubescent, sometimes puberulent to glabrescent in apical leaves of flowering stems, margin with trichomes, base cuneate to obtuse, apex acute or sometimes obtuse. Spikes 5–18.5 cm long, 2 to 5 grouped, terminal and axillar in apical and sub-apical leaves, straight or incurved; peduncle 1–2.7 cm long, pubescent; rachis 3.5–16 cm long, glabrous, smooth, loosely flowered; bracts 0.5–0.75 mm diam., circular, margin entire. Fruits ca. 0.75 mm long, globose – ovoid, on a pseudopedicel, not in pits, papillate, glabrous, pseudocupule absent.

Subgenus:— This species belongs to the subgenus Micropiper ( Frenzke et al. 2015) .

Distribution and habitat:— Argentina, Bolivia, Paraguay and Uruguay. In the Southern Cone occurs from northern to central Argentina (Buenos Aires, Chaco, Corrientes, Entre Ríos, Formosa, Jujuy, Santa Fe), northern Paraguay (Alto Paraguay) and western Uruguay (Artigas, Paysandú, Río Negro). In Uruguay the distributional range is probably underestimated because the species is poorly sampled ( Fig. 2B ). It occurs in open thorn forest associated to halomorphic soils, where it grows as a terrestrial plant under trees. Less commonly it has been recorded as an epiphyte on Prosopis sp.

Phenology:— Developing spikes were observed from late December, flower anthesis from January to March and mature fruits from March.

Conservation assessment:— This species was categorized in the AOO analysis as Vulnerable (VU) for Uruguay. It shows a restricted distribution in the western of the country, occurring only in open thorn forest associated to halomorphic soils, which is a threatened environment especially for agricultural activities and logging ( Marchesi et al. 2013). Thus, this species was previously considered a priority for conservation in the country ( Marchesi et al. 2013). The examined material was from the buffer area of ‘Parque Nacional Esteros de Farrapos e Islas del Río Uruguay’, thus, in this site the species apparently could have some means of protection.

Distinctive and field characters:— Peperomia comarapana is characterized by verticillate and pubescent leaves together with the presence of two or more spikes grouped apically. Moreover, P. comarapana is the only Peperomia species that develops in the halomorphic soils of western Uruguay. Living plants show reddish stems, petioles and abaxial surface of basal leaves. The basal leaves have longer petioles and smaller and thicker leaf blades than the apical leaves. The central spike is longer and develops earlier than lateral spikes.

Related taxa:— This species is close to Peperomia santaelisae C. DC. , which inhabits a similar habitat near Uruguay, in Buenos Aires and Entre Ríos provinces ( Argentina). According to Burkart (1951), Yuncker (1953) and Zanotti (2012), P. santaelisae is mainly separated from P. comarapana by shorter petioles and wider leaves.

Background in Uruguay:— It was mentioned for the first time for Uruguay by Alonso Paz (1989).

Specimens examined:— URUGUAY. Artigas: Estancia Silva y Rosas, litoral W del Río Uruguay , [30º34’48”S, 57º47’60”W], 22 January 2013, Berazategui et al. s.n. (MVM 23008). Paysandú: San Félix, [32º21’S, 58º6’W], 27 March 1983, Alonso Paz 750 (MVFA). Río Negro: Estancia Mafalda, [32º52’S, 58º2’W], 20 March 1993, Marchesi s.n. (MVFA 21886) ; Estancia Mafalda , [32º52’S, 58º2’W], 26 March 1993, Marchesi s.n. (MVFA 21860) ; Cultivated plant collected in Estancia Mafalda , [32º52’S, 58º2’W], 19 February 2014, Fagúndez s.n. (MVJB 29283) ; Cultivated plant collected in Zona adyacente al Área Protegida Esteros de Farrapos , 32º45’37’’S, 58º5’9’’W, 26 February 2014, Rossado & Mai 350 (MVJB) .

Additional specimens examined:— ARGENTINA. Chaco: Colonia Benitez, [27º20’7’’S, 58º57’4’’W], 11

March 1970, Schulz 17351 (CTES); La Clotilde, [27º10’18’’S, 60º37’53’’W], 17 March 1952, Schulz 8210 (CTES).

Corrientes: Paso de los Libres, 2 Km NE del Río Miriñay por Ruta 127, [29º57’18’’S, 57º39’29’’W], 16 February 1979, Schinini et al. 17286 (CTES). Formosa: Bartolomé de las Casas, [25º24’38’’S, 59º34’00’’W], March 1971, Insfrán 740 (CTES).

3. Peperomia hispidula var. sellowiana (Miq.) Dahlstedt (1900: 14) ≡ Peperomia tenera Miquel in Martius (1852: 19) ≡ Acrocarpidium sellowianum Miquel (1843: 55) . Type:—(holotype B, destroyed). Lectotype (designated by Zanotti et al. 2012):— BRAZIL. Brasilia: Sellow s.n (U-0112686 on-line image!, isolectotypes G not seen, K-000324725 on-line image!, W-0059180 on-line image!) ( Fig. 4 )

Herbs, terrestrial. Stems erect, decumbent or spreading, cylindrical (live), glabrous, nodes pubescent, adventitious roots only present in the base. Leaves alternate; petiole 0.4–1 cm long, with trichomes grouped near the leaf blade; leaf blade 0.6–1.5 × 0.8–1.5 (–2) cm, membranous, thin when dry, orbicular to obovate–orbicular, 5–veined, veins forked towards the apex, prominent abaxially, abaxial and adaxial surface with scattered hispid trichomes, margin glabrous, base rounded, apex rounded to obtuse. Spikes 1–2 cm long, solitary, leaf–opposed or terminal, slender, straight when flowers, curved when fructifies; peduncle 0.7–1 cm long, pubescent; rachis 0.7–0.8 cm long, glabrous, smooth, loosely flowered; bracts 0.2–0.3 mm diam., circular. Fruits ca. 1 mm long, globose, on a stipe when mature, not in pits, smooth with white hispid trichomes, pseudocupule absent.

Subgenus:— This species belongs to the subgenus Hispidulae ( Frenzke et al. 2015) .

Distribution and habitat:— Argentina, Brazil and Uruguay.In the Southern Cone occurs in northeastern Argentina (Misiones), southern Brazil (Paraná, Rio Grande do Sul, Santa Catarina) and northeastern Uruguay (Tacuarembó). In Uruguay it is found in moist hillside forests, growing among mud and humus in wet and shady places. Its distribution range in Uruguay is locally restricted, as it was solely recorded within certain ravines of Tacuarembó ( Fig. 2C ).

Phenology:— Herbarium specimens were observed with flowers in May, October, November and December, and with mature fruits in August, November, December and January.

Conservation assessment:— This species was categorized in the AOO analysis as Endangered (EN) for Uruguay. It shows a restricted distribution in the country, occurring only in some ravines close together. Thus, this species was previously considered a priority for conservation in the country ( Marchesi et al. 2013). It is not present in any of the protected areas of the S.N.A.P., however one of the ravines in which it develops is appreciated and preserved by the current owner.

Distinctive and field characters:— In Uruguay Peperomia hispidula var. sellowiana can be easily distinguished from other species of the genus by its alternate leaves. Furthermore, this species is the only taxon in the country with pilose fruits. It presents notorious and characteristic scattered trichomes on the leaf, which stand out on the laminar tissue for their expanded base and whitish color.

Background in Uruguay:— Trelease (1941) and Trelease & Herter (1952) mentioned Peperomia tenera for Uruguay, and later Marchesi (1968) cited P. hispidula (Sw.) A. Dietr.

Specimens examined:— URUGUAY. Tacuarembó: Gruta de los Cuervos , [31º37’12”S, 56º2’24”W], 3 January 1960, Rosengurtt B –7947 (MVFA) ; Gruta de los Cuervos , [31º37’12”S, 56º2’24”W], 9 March 1966, Rosengurtt et al. 9979 (MVFA) ; Gruta de los Helechos , [31º37’S, 56º1’W], 24 December 1901, Berro 1916 (MVFA) ; Gruta de los Helechos , [31º37’S, 56º1’W], 16 May 1984, Brussa et al. s.n. (MVJB 20536) ; Gruta de los Helechos , [31º37’S, 56º1’W], 15 October 1986, Brussa et al. s.n. (MVJB 20542) ; Puntas de Cinco Sauces , 31º57’38.17’’S, 55º00’42.44’’W, 26 August 2010, Brussa et al. s.n. (MVJB 27795) ; Puntas de Cinco Sauces , 31º58’2.5’’S, 55º1’18.1’’W, 7 November 2013, Brussa & Álvarez s.n. (MVJB 28710) .

Additional specimens examined:— BRAZIL. Rio Grande do Sul: Encruzilhada do Sul , [30º33’S, 52º30’W], 16 December 2007, Grings 442 (ICN) ; Pessegueiro, Camaquã , [30º36’33”S, 51º50’36”W], October 1983, Sobral 2413 (ICN) ; São Francisco de Paula, Floresta Nacional FLONA-SFP, 923 m, [29º25’22’’S, 50º23’11’’W], 19 August 2006, Seger 245 (ICN) .

4. Peperomia increscens Miquel (1847: 124) . Type:— BRAZIL. Goiás: Ad Eugenio da Verge, Pohl 5040 (holotype W-0024290 on-line image!) ( Fig. 3 )

= Peperomia blanda var. pseudodindygulensis (C. DC.) Yuncker (1953: 218) ≡ Peperomia pseudodindygulensis A. C. P. de Candolle (1882: 307) . Type:— PARAGUAY. Santa-Bárbara, dans les forêts humides, 26 February 1876, Balansa 2626 (holotype G-00324796 on-line image!).

Herbs, terrestrial, epipetric and sometimes epiphytic. Stems erect and stoloniferous, cylindrical (live), pubescent, adventitious roots only present in the base. Leaves mostly opposite, sometimes 3(4) verticillate towards the apex of flowering stems; petiole 6–12 mm long, tomentose; leaf blade (0.9–) 2–5.7 × 0.9–3.8 cm, slightly succulent, elliptic, rhombic–elliptic, rhombic-obovate or obovate, 3 to 5–veined, veins visible, sometimes prominent abaxially, abaxial and adaxial surface pubescent, margin with trichomes, base cuneate to rounded, occasionally asymmetric, apex obtuse to rounded. Spikes 7–16 cm long, (1) 2 to 6 (7) grouped, terminal and axillary in apical and subapical leaves, straight when flowers, curved when fructifies; peduncle 0.8–1.7 cm long, with scattered trichomes; rachis (4.7–) 5.7–14.5 cm long, glabrous, smooth, loosely flowered; bracts 0.5–1 mm diam., circular to ovoid, margin slightly irregular. Fruits 0.75–1 mm long., globose, on a pseudopedicel, not in pits, papillate, glabrous, pseudocupule absent.

Subgenus:— This species belongs to the subgenus Micropiper ( Frenzke et al. 2015) .

Distribution and habitat:— Argentina, Brazil, Bolivia, Paraguay and Uruguay. In the Southern Cone occurs in northern and central Argentina (Catamarca, Chaco, Córdoba, Corrientes, Entre Ríos, Formosa, Jujuy, Misiones, Salta, Santa Fe, Tucumán), southern Brazil (Paraná, Rio Grande do Sul, Santa Catarina), Paraguay (Alto Paraguay, Cordillera, Guairá, Ñeembucú, Presidente Hayes) and northeastern, eastern and southeastern Uruguay (Artigas, Cerro Largo, Rivera, Rocha, Tacuarembó) ( Fig. 2B ). In Uruguay it grows in xeric hillside and moist hillside forests, in humid, shady or semi-shaded places. It usually grows on the ground or on rocks and less commonly on tree trunks.

Phenology:— Developing spikes were observed from December, flower anthesis from January to April and mature fruits from February. Fruits remain on the rachis for a long time, as were observed specimens with mature fruits in February, March, April, June and November.

Conservation assessment:— This species was categorized in the AOO analysis as Near Threatened (NT) for Uruguay. In the country, it is present in three disjunct areas with relative low number of records in each one. Although it could be subsampled, the category of NT is reasonable considering the current knowledge of the species for the country. Peperomia increscens occurs in the protected area ‘Paisaje protegido Valle del Lunarejo’.

Distinctive and field characters:— In Uruguay Peperomia increscens differs from other species of the genus by its mostly opposite leaves (the apex of fertile stems sometimes has up to 4 verticillate leaves). Living plants show reddish stems and a velvety leaf surface. The central spike is longer and develops earlier than lateral spikes. Mature fruits are sticky.

Background in Uruguay:— The presence of this species was mentioned for the first time in Uruguay by Marchesi (1968) under the name Peperomia blanda var. pseudodindygulensis .

Specimens examined:— URUGUAY. Artigas: Cultivated plant collected in Aº Invernada, 30°47’47.9”S, 56°1’38.24”W, 19 February 2015, Brussa et al. s.n. (MVJB 29437). Cerro Largo: Camino Sierra de Ríos entre Ruta 7 y cerco de piedra, [32°12’24.3”S, 53°48’12.0”W], 13 June 1999, Brussa & Grela s.n. (MVFA 29243). Rivera: Cañada de la Aurora, 30º58’16.75’’S, 55º43’33.18’’W, 11 April 2013, Mai & Rossado 297 (MVJB) ; 12 Km SE de Masoller, [31°08’43”S, 55°56’57”W], 17 February 2010, Meza Torres et al. 1278 (CTES) ; Río Tacuarembó (nacientes), 30º56’33.27’’S, 55º38’43.92’’W, 11 April 2013, Mai et al. 289 (MVJB) ; Subida de Pena, Ruta 30 km 109, [31º08’27’’S, 55º54’24’’W], 11 November 1984, Bayce et al. s.n. (MVFA 17275) ; Valle del Aº Platón, próximo a Escuela Nº 56, [30º59’33’’S, 55º41’15’’W], 21 February 1966, Marchesi 1486 (MVFA). Rocha: Santa Teresa, mirador del Mangrullo, 34º0’55.01’’S, 53º33’25.43’’W, 7 March 2014, Mai & Gutiérrez 367 (MVJB) ; Sierra de los Difuntos , 34º05’13’’S, 53º47’20.5’’W, 22 April 2015, Rossado et al. 416 (MVJB). Tacuarembó: Cultivated plant collected in Gruta de los Helechos, [31º37’S, 56º1’W], 11 February 2015, Mai & Delfino 369 (MVJB) .

Additional specimens examined:— ARGENTINA. Corrientes: Capital, Aº Riachuelo y Ruta 12, [27º33’13’’S, 58º45’03’’W], 15 October 1974, Cristóbal et al. 1162 (CTES) ; Empedrado, Estancia “La Yeta”, 20 May 1965, Pedersen 3918 (CTES) ; Saladas, San Lorenzo , [28º07’S, 58º46’W], 20 April 1973, Schinini 6310 (CTES) ; San Cosme, Ingenio Primer Correntino , 29 April 1974, Benitez et al. 147 (CTES) ; Santo Tomé, Garruchos, costa del Río Uruguay , [28º10’38’’S, 55º38’48’’W], 12 April 1974, Krapovickas et al. 22869 (CTES). Formosa: Pilcomayo, Ruta 11 al N del km 103, [25º40’S, 57º57’W], 23 July 1947, Morel 3590 (CTES). Jujuy: Capital, Tunal, 9 March 1983, Rotman et al. 644 (CTES). Misiones: Candelaria, El Edén, Bonpland, [27º28’S, 55º28’W], 10 February 1969, Krapovickas et al. 14829 (CTES). Salta: Orán, Pasando Yaculika a más o menos 5 km Arroyo El Arasayal, 22 February 1977, Legname et al. 5282 (CTES). Tucumán: Tafí, Camino a Tafí del Valle , [26º51’S, 65º42’W], 21 April 1970, Meyer & Vaca 23226 (CTES) . BRAZIL. Rio Grande do Sul: Pelotas , [31º45’S, 52º17’W], 22 January 1973, Krapovickas et al. 22869 (CTES) .

5. Peperomia pereskiifolia (Jacq.) Kunth ([1815] 1816: 68) (“ pereskiaefolia ”) ≡ Piper pereskiifolium Jacquin (1790: 126) . Lectotype (designated by Mathieu & Callejas 2006):—“Hort. Schönbr” [material cultivated in Hortus Botanicus Schoenbrunnensis, Vienna, Austria], Jacquin s.n. (W-0024721 on-line image!) ( Fig. 5 )

Herbs, epiphytic and epipetric. Stems repent and pendant, sometimes decumbent, cylindrical or slightly angular (live), glabrous, adventitious roots present in base and nodes. Leaves (2) 3 to 6 (7) verticillate; petiole 3–12 mm long, glabrous; leaf blade (2–) 2.6–5.3 × 1.2–2.7 cm, coriaceous and slightly succulent, elliptic, elliptic-rhombic or obovate, sometimes obtuse, 3–veined, veins visible, markedly prominent abaxially, abaxial and adaxial surface glabrous, margin glabrous, base narrowly cuneate to cuneate, apex acute or acuminate. Spikes 9–16 cm long, solitary or 2 to 4 grouped, terminal, curved; peduncle 2–6.2 cm long, glabrous; rachis 7–11 cm long, glabrous, smooth, loosely flowered; bracts 0.3–0.5 mm. diam., circular to elongate, margin entire or slightly irregular. Fruits 0.75–1 mm long, globose–ovoid, sessile but on a pseudopedicel when mature, emerging from pits of the rachis, smooth, glabrous, pseudocupule viscose on the basal half.

Subgenus:— This species belongs to the subgenus Pseudocupula ( Frenzke et al. 2015) .

Distribution and habitat:— Belize, Brazil, Colombia, Costa Rica, Ecuador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Uruguay and Venezuela. In the Southern Cone occurs in southern Brazil (Paraná, Rio Grande do Sul, Santa Catarina), northeastern Paraguay (Canindeyú) and southeastern Uruguay (Rocha). The distribution in Uruguay is currently restricted to forests near Laguna Negra (Rocha), which represents the southern limit of distribution for this species ( Fig. 2D ). It was found in psammophilous and moist hillside forest growing on rocks, trunks and large branches. The species may occur in other localities along the coastal plain of the country due to the presence of similar vegetation and environmental. Habitat and distribution knowledge of this species in Uruguay could be improved with additional sampling.

Phenology:— Developing spikes were observed from December and flower anthesis from January to April. Fruits were observed only from one herbarium specimen collected in July.

Conservation assessment:— This species was categorized in the AOO analysis as Endangered (EN) for Uruguay. It shows a restricted distribution, occurring only in the forest associated to Laguna Negra. Thus, this species was previously considered a priority for conservation in the country ( Marchesi et al. 2013). It is not present in any of the protected areas of the S.N.A.P., however the localities where the species occurs in Laguna Negra, are inside the ‘Reserva de Biosfera Bañados del Este’—Ramsar Site, and have protection measures.

Distinctive and field characters:— Within Uruguay, Peperomia pereskiifolia can be distinguished by its relatively large (longer than 2.6 cm) and completely glabrous leaves. Live plants usually have reddish stems, petioles and peduncles. The central spike is longer and develops earlier than lateral spikes.

Background in Uruguay: The first citation for this species in Uruguay appeared in Zuloaga et al. (2008), without mention of a supporting voucher or reference bibliography. The first herbarium sample of this species for Uruguay is from Santa Teresa (Rocha), probably collected from material in cultivation (Lombardo 4630, MVJB). Currently, there are only five herbarium specimens from two localities with natural habitats that confirm the species in the country.

Specimens examined:— URUGUAY. Rocha: Potrerillo , [33º58’25’’S, 53º38’52’’W], 5 July 1994, Alonso Paz 4680 (MVFQ) ; Potrerillo , 33º58’23’’S, 53º38’57’’W, 28 November 2013, Fagúndez et al. s.n (MVJB 29059) ; Potrerillo , 33º58’23’’S, 53º38’53’’W, 28 November 2013, Fagúndez et al. (MVJB 29060) ; Cultivated plant collected in Potrerillo , 33º58’23’’S, 53º38’57’’W, 8 April 2014, Rossado & Mai 354 (MVJB) ; Sierra de los Difuntos , [34º05’08’’S, 53º45’12’’W], 11 February 2006, Bonifacino & Puppo 2172 (MVFA) .

Additional specimens examined:— BRAZIL. Paraná: Ibiporã, Fazenda Doralice , [23º15’S, 51º03’W], 14 November 1989, Colii et al. s.n. (ICN 172430) ; São Pedro do Ivaí, Fazenda Barbacena, [23º51’S, 51º50’W], 11 October 2003, Ribas et al. 5577 (CTES). Rio Grande do Sul: Tramandaí , [29º57’S, 50º08’W], 19 March 1976, Citadini et al. 69 (ICN) . PARAGUAY. Canindeyú: Lagunita Sendero del Aº Moroti , [24º07’44’’S, 55º25’37’’W], 3 October 1997, Marín & Jiménez 632 (CTES) ; Reserva Natural Mbaracayú , 24º08’34’’S, 55º31’60’’W, 5 December 2003, Múlgura de Romero et al. 3531 (CTES) .

6. Peperomia psilostachya A. C. P. de Candolle (1893: 9) . Type:— PARAGUAY. Cerro d’Acahy, Croissant sur le tronc des arbres, 1 December 1883, Balansa 4533 (holotype P-00468104 on-line image!) ( Fig. 1 )

= Peperomia trapezoidalis Yuncker (1953: 202) , syn. nov. Type: — ARGENTINA. Misiones: Depto. San Javier, Acaragua (Alto Uruguay), Sobre corteza de arboles corp., 200 m, 30 January 1947, Bertoni 2339 (holotype LIL-000272 on-line image!, isotype NY-00250678 on-line image!).

Herbs, epiphytic. Stems repent and pendant, cylindrical (live), puberulous, adventitious roots present in base and nodes. Leaves (2) 3 to 5 (6) verticillate; petiole 1–1,5 mm long, puberulous; leaf blade 0.6–0.8 × 0.4–0.6 cm, succulent, rhombic to rhombic–elliptic, 3–veined, midrib prominent on abaxial surface, abaxial surface puberulous, adaxial surface generally glabrous, margin with trichomes, base cuneate, apex obtuse or slightly cuspidate. Spikes 4–8 cm long, solitary, terminal, straight; peduncle 1.8–4 cm long, puberulous; rachis 2.2–4 cm long, glabrous, smooth, densely flowered; bracts ca. 0.5 mm diam., circular, margin slightly irregular. Fruits ca. 1 mm long., globose–conic, sessile but on a pseudopedicel when mature, emerging from pits of the rachis, smooth, glabrous, pseudocupule viscose on the basal half.

Subgenus:— This species belongs to the subgenus Pseudocupula ( Frenzke et al. 2015) .

Distribution and habitat:— Argentina, Bolivia, Brazil, Paraguay and Uruguay. In the Southern Cone occurs in northeastern Argentina (Corrientes, Misiones), southern Brazil (Paraná, Rio Grande do Sul), eastern Paraguay (Canindeyú, Guairá, Paraguarí) and northeastern and eastern Uruguay (Cerro Largo, Rivera). Its distribution range in Uruguay is locally restricted thus far, as it was only recorded at two sites close to the border with Brazil. The record from Río Yaguarón represents the southernmost limit for this species ( Fig. 2D ). In Uruguay it grows in moist hillside and well-developed riverside forests. It was found in low abundance and growing in semi-shaded places on trunks and large branches of Luehea divaricata Martius (1824: 101) .

Phenology:— Herbarium specimens were observed with fruits in February.

Conservation assessment:— This species was categorized in the AOO analysis as Endangered (EN) for Uruguay. It shows a restricted distribution in the east of the country, occurring in well-developed forests susceptible to human activities, and is not present in any of the protected areas of the country.

Distinctive and field characters:— This species is characterized by its repent and pendant stems and relatively small rhombic to rhombic–elliptic blades. We observed in the field extensive plants with pendant stems approximately 50 cm long. Occasionally the abaxial surface of some leaves show light green lines along the veins.

Taxonomic observation:— Yuncker (1953) published Peperomia trapezoidalis and stated as characteristic features for the species “the small, nearly square leaves, puberulent stems and leaves and slender petiole of varying length, and rather long peduncle”. In our opinion all these features are shared with P. psilostachya . Additionally, Yuncker (1953) presents a key where he distinguishes both species by the leaf shape, P. psilostachya with ovate to rhombic-ovate leaves and obtuse to subcordulate base, while P. trapezoidalis with elliptic, rhombic or ellipticovate leaves and acute base. He also added herbarium specimen photographs of both species, where these vegetative differences can be observed. Nevertheless, both the selected specimen photograph and the features attributed to P. psilostachya (sensu Yuncker 1953) show marked differences from the type material and the original description of the species. Given these differences we conclude that Yuncker (1953) misinterpreted P. psilostachya and so described P. trapezoidalis as a new species. Interestingly, in Yuncker (1974), P. psilostachya is interpreted in accordance with the holotype. In our view, the type materials of P. trapezoidalis concur completely with the original description and with the type of P. psilostachya , and so we synonymize P. trapezoidalis to the earlier name P. psilostachya .

Background in Uruguay:— This work is the first citation of this species for Uruguay.

Specimens examined:— URUGUAY. Cerro Largo: Río Yaguarón, cerca Centurión , 32º4’41’’S, 53º46’4.5’’W, 22 February 2013, Mai et al. 205 (MVJB) ; Río Yaguarón, cerca Centurión , 32º4’43’’S, 53º46’1’’W, 22 September 2013, Mai et al. 347 (MVJB). Rivera: Cañada de la Aurora, 30º58’22.6’’S, 55º43’26.6’’W, 11 April 2013, Mai & Rossado 298 (MVJB) .

Additional specimens examined:— ARGENTINA. Corrientes: Estancia Garruchos, Aº Chimiray , [28º8’S, 55º38’W], 8 February 1972, Krapovickas et al. 21351 (CTES) ; Río Aguapey y Ruta 38, [29º6’3’’S, 56º36’25’’W], 27 April 1985, Schinini et al. 24338 (CTES). Misiones: Aº El Paraíso y Ruta 2, 27º8’S, 54º5’W, 23 September 1993, Rodríguez et al. 711 (CTES) ; Camping Municipal de Alem , 22 November 1986, Cabral & Zamudio 492 (CTES) ; Parque Nacional Iguazú , [25º41’S, 54º12’W], 22 April 1997, Morrone et al. 2023 (CTES) ; Paso Carreta , [27º34’S, 55º19’W], 9 March 1969, Krapovickas et al. 15001 (CTES) ; Predio Guaraní , [26º54’59’’S, 54º12’18’’W], 16 September 1998, Keller 3069 (CTES) . BRAZIL. Rio Grande do Sul: Eldorado do Sul, Estación Experimental Agronomica da UFRGS, [30º5’S, 51º40’W], 19 December 2001, Waechter & Giongo 223 (ICN) ; Júlio de Castilhos , [29º13’S, 53º42’W], 2 April 2008, Grings 488 (ICN) ; Mun. Dois Irmãos, Rio Feitoria , [29º35’3’’S, 51º9’10’’W], 27 January 1983, Bueno & Krapovickas 3606 (CTES) ; Santa Cruz do Sul, Trombudo , [29º43’S, 52º24’W], 18 February 1980, Waechter 1558 (ICN) ; Salto do Jacuí , [29º4’19’’S, 53º13’5’’W], 5 April 2008, Grings 490 (ICN) . PARAGUAY. Canindeyú: Reserva Natural Mbaracayú, Jejui-mí , [24º7’44’’S, 55º25’37’’W], 26 March 1996, Marín & Jiménez 59 (CTES) ; Guazurí, camino a Puerto Adela , [24º28’S, 54º24’W], 17 March 1982, Schinini 23154 (CTES) .

7. Peperomia tetraphylla Hooker & Arnott (1832: 97) . Lectotype (designated by Florence 1997): — SOCIETY ISLANDS. August 1885, Forster s.n. (K-000820323 on-line image!, isolectotypes C not seen, LE-00018148 image!) ( Fig. 4 )

= Peperomia reflexa (L. f.) A. Dietrich (1831: 180), nom. illeg. non Kunth (1815 [1816]: 70–71) ≡ Piper reflexum Linnaeus f. (1781: 91) . Type: — SOUTH AFRICA. Western Cape: Thunberg s.n. (holotype UPS-752 image!).

= Peperomia berroi Trelease (1941: 67) . Type: — URUGUAY. Cerro Largo: Sierra de Rios, Crescit in rupibus umbrosis, 28 November 1909, Berro 5753 (holotype K-001089666 on-line image!, isotypes MVFA-0000009!, MVFA-0001047!, MVFA-0001048!).

= Peperomia tacuariana Trelease (1941: 66) . Type: — Herter 14 (holotype ILL, missing). Lectotype (designated here): — URUGUAY. Cerro Largo: Sierra de Ríos , February 1937, Herter s.n. in Herb. Herter 98370 (ILL-00009104 on-line image!, isolectotypes MO-1153321 image!, G-00382714 image!, G-00382715 image!).

= Peperomia americana (Miq.) Herter (1952: 46) ≡ Peperomia reflexa (L. f.) A. Dietrich (1831: 180) fo. americana Miquel (1843: 173) . Type: — VENEZUELA. Caracas: Bredemeyer s.n., in Herb. Willd. 753 fo. 3. (holotype [B] B-W-00753-030 on-line image!).

= Peperomia arechavaletae var. minor Herter in Marchesi (1968: 10), syn. nov. Lectotype (designated here): — URUGUAY. Treinta y Tres: Tacuarí, at Luehean divaricatam ingentem. Magnit. 20 cm. Fl.—Fr. Albid-vir, November 1933, Herter s.n. in Herb. Herter 94031 (LAU image!, duplicate MO, missing). Peperomia arechavaletae var. minor Herter (1952: 45) , nom. inval.

Herbs, epiphytic and epipetric. Stems erect, decumbent and sometimes repent, cylindrical (live), puberulous, adventitious roots present in base and nodes. Leaves 3–4 verticillate; petiole 1–3 mm long, pubescent; leaf blade 0.8– 1.7 (1.9) × 0.6–1.2 cm, slightly succulent to succulent, rhombic–elliptic, rhombic–obovate, rhombic–ovate or widely elliptic, 3–veined, veins notorious, not prominent, abaxial surface puberulous, adaxial surface glabrous or glabrescent and generally with light green or whitish lines along the veins, margin with trichomes, base cuneate or obtuse, apex rounded or obtuse. Spikes 2.0– 6 cm long, solitary, terminal, straight or slightly curved; peduncle 0.8–1.8 cm long, puberulous; rachis (1.2–) 1.8–4.2 cm long, strongly hirsute, densely flowered; bracts ca. 0.5 mm diam., circular to widely rhombic, margin entire. Fruits ca. 1 mm long., globose–cylindrical, sessile, located in pits of the rachis, smooth, glabrous, pseudocupule viscose on the basal half.

Subgenus:— This species belongs to the subgenus Pseudocupula ( Frenzke et al. 2015) .

Distribution and habitat:— Pantropical distribution, occurs in tropical Africa, Asia and Oceania, and in America occurs from Mexico to Uruguay. In the Southern Cone occurs in northern Argentina (Catamarca, Jujuy, Misiones, Salta, Tucumán), southern Brazil (Paraná, Rio Grande do Sul, Santa Catarina), northern and eastern Paraguay (Alto Paraná, Caazapá) and northeastern, eastern and southeastern Uruguay (Cerro Largo, Maldonado, Rivera, Rocha, Treinta y Tres). Peperomia tetraphylla along with P. catharinae are the most widely distributed species of the genus in Uruguay. The southern limit of the distribution in America is in Maldonado and Rocha departments, with Cerro de las Ánimas (Maldonado) the southernmost locality where this species was registered ( Fig. 2C ). In Uruguay it is found in moist hillside, hydrophilous and riverside forests, where it has variable abundance from rare to very common. It grows on rocks, trunks, branches and bifurcations of branches of several tree species.

Phenology:— Developing spikes were observed from February, flower anthesis from late March to June and mature fruits as of September.

Conservation assessment:— This species was categorized in the AOO analysis as Least Concern (LC) for Uruguay. It is a common species with high frequency throughout its distribution range in the country. It occurs in two protected areas ‘Paisaje Protegido Quebrada de los Cuervos’ and ‘Parque Nacional San Miguel’.

Distinctive and field characters:— Peperomia tetraphylla is the only species in the country with trichomes on the spike rachis, especially notorious in the fruiting period. Additionally, the species is easy to recognize in the field by the light green lines along the veins on the adaxial surface of the leaves. In the flowering period, the erect and thick rachis with whitish bracts that contrast with the thin and green peduncle are very characteristic. We observed in some plants that the basal leaves are fleshier than the upper leaves and do not show the light green lines. Mature fruits are brown and sticky.

Background in Uruguay:— Peperomia tetraphylla was mentioned for Uruguay as P. berroi (Trelease 1941; Trelease & Herter 1952), P. tacuariana (Trelease 1941; Trelease & Herter 1952), P. americana ( Trelease & Herter 1952) and P. reflexa ( Yuncker 1958; Marchesi 1968).

Taxonomic observation I:— We did not include infraspecific categories since this species shows a wide variation in shape, size and pubescence of leaves and stems, which are the main features used to discriminate the varieties. Here we include Peperomia americana as a synonym of P. tetraphylla although it is in fact a synonym of P. tetraphylla var. americana (Dahlst.) Yunck. ( Yuncker 1974) .

Taxonomic observation II:— The protologue of Peperomia arechavaletae var. minor ( Trelease & Herter 1952) , includes a Latin diagnosis and reference specimens, but the name was not validly published since it was proposed in anticipation “ ad int. ” of the future acceptance of the taxon concerned (ICN Art. 36.1(b); McNeill et al. 2012). The designation was validated by Marchesi (1968), as he accepted the name P. arechavaletae var. minor in reference to Trelease & Herter (1952), excluding the term “ ad int. ”. In our view the type material chosen by Herter in 1952 for P. arechavaletae var. minor corresponds entirely to P. tetraphylla . Therefore we synonymize P. arechavaletae var. minor to P. tetraphylla .

Type observations I:— In the protologue of Peperomia arechavaletae var. minor the type material is mentioned as Herb. Hert. 94031 in the herbaria LAU and MO, thus representing two syntypes. The LAU herbarium specimen is a complete sample and now the only available, since the MO syntype was not found (Jim Solomon com. pers.). In this context, we designated the LAU specimen as the lectotype for P. arechavaletae var. minor .

Type observations II:— The holotype of Peperomia tacuariana was not found in ILL (David Seigler com. pers.), where the Herb. Trel. is located. Nevertheless, after a detailed review of the diagnosis and taking into account the locality of the type material, we include this name as a synonym of P. tetraphylla , in agreement with Marchesi (1968). In P. tacuariana protologue, under the editor’s note, four paratypes are included: Herb. Hert. 90961 (ILL, LAU, Z); Herb. Hert 94035a; Herb. Hert. 98388 (G, ILL) and Herb. Hert. 98370 (G, ILL, MO). The herbarium specimen Herb. Hert 94035a was not found and Herb. Hert. 90961 and Herb. Hert. 98388 correspond to P. catharinae , so they are discarded as type material of P. tacuariana . Here we designate as a lectotype of P. tacuariana the specimen Herb. Hert. 98370 (ILL), as the size and shape of the leaves clearly fit the diagnosis of the species, despite the absence of reproductive structures.

Specimens examined:— URUGUAY. Cerro Largo: Cuchilla del Yaguarón, 32º10’22.3’’S, 53º51’40.6’’W, 22 February 2013, Mai et al. 217 (MVJB); Río Yaguarón, cerca de Centurión, 32º04’41.1’’S, 53º46’4.5’’W, 22 February 2013, Mai et al. 204 (MVJB); Sierra de Ríos, [32°12’24”S, 53°48’11”W], 28 December 1909, Berro 5753 (MVFA). Maldonado: Cerro de las Animas, [34°44’30”S, 55°19’7”W], 14 December 1899, Berro 1213 (MVFA). Rivera: Aº Rubio Chico, 31º7’56’’S, 55º54’47.8’’W, 12 April 2013, Mai et al. 306 (MVJB); Cañada de la Aurora, 30º58’14.5’’S, 55º43’33.6’’W, 11 April 2013, Mai & Rossado 299 (MVJB); Río Negro (cerca límite con Brasil), 31º49’8.6’’S, 54º27’40’’W, 23 February 2013, Mai et al. 235 (MVJB). Rocha: Estancia el Palmar cerca de Castillos, [34°10’57”S, 53°47’35”W], 20 March 1977, Marchesi s.n. (MVFA 14059); Parque San Miguel, [33°42’34”S, 53°34’36”W], 6 October 1965, Del Puerto & Marchesi s.n. (MVFA 5261); Parque Nacional San Miguel, 33º42’53’’S, 53º33’48’’W, 14 October 2012, Rossado 15 (MVJB); Puerto de la Cristina, Cebollatí, [33°11’37”S, 53°45’4”W], 28 January 1989, Marchesi et al. s.n. (MVFA 19432); Sierra de la Blanqueada, 33º58’18’’S, 53º51’15’’W, 22 September 2012, Mai et al. 1 (MVJB); Sierra de la Blanqueada, 34º00’8.3’’S, 53º52’42.7’’W, 3 April 2014, Haretche 738 (MVJB). Treinta y Tres: costas del Río Cebollatí, frente a la bomba de Ferres, [33°20’11”S, 53°54’12”W], 29 January 1989, Marchesi et al. s.n. (MVFA 19435); Quebrada de los Cuervos, [32°55’10”S, 54°27’22.9” W], 1 November 1964, Marchesi 1286 (MVFA).

Additional specimens examined:— ARGENTINA. Misiones: Cruce Caballero , 26º32’12.5’’S, 53º57’38.7’’W, 19 March 2011, Keller & Paredes 10028 (CTES) ; Eldorado, Ruta provincial 17 Aldea Aborigen Pozo Azul , [26º20’S, 54º27’W], 28 May 2002, Keller & Gatti 1843 (CTES) ; General San Martín, Ruta Prov. 220, 21 Km al N acceso a Aristóbulo del Valle , [26º57’S, 54º51’W], 1 Ago 1987, Vanni et al. 958 (CTES) ; Iguazú , 25º45’S, 54º15’W, 16 May 1996, Amarilla et al. 50 (CTES) ; Paraje Paraíso, Aldea Aborigen Guavira Poty , 5 June 2002, Keller 1887 (CTES) ; Parque Provincial Cruce Caballero, Sendero Curi-y , 26º31’8.1’’S, 53º59’20.2’’W, 626 m, 5 March 2013, Judkevich et al. 19 (CTES) ; Predio Guaraní, picada al Aº Soberbio , 26º54’59’’S, 54º12’18’’W, 23 August 1996, Tressens et al. 5635 (CTES) ; Reserva de Biósfera Yabotí, Parque Provincial Esmeralda , [26º50’S, 54º02’W], 30 September 2003, Keller 2441 (CTES) ; San Pedro, Parque Provincial Moconá , 26º38’31’’S, 53º57’36’’W, 16 December 1992, Seijo et al. 188 (CTES) . BRAZIL. Paraná: Alto Paraná, Reserva Biológica Itabo, 3 Km W río Paraná, 25º5’S, 54º5’W, 9 October 1990, Schinini & Caballero Marmori 27010 (CTES) ; Marmeleiro, [26º8’S, 53º2’W], 31 March 1983, Kummrow 2274 (CTES). Rio Grande do Sul: Parque Estadual Turvo, Ten. Portela , [27º11’45’’S, 53º53’26’’W], 10 July 1980, Waechter 1640 (CTES) .

8. Peperomia trineuroides Dahlstedt (1900: 198) . Type: — BRAZIL. Rio Grande do Sul: Santo Angelo pr. Cachoeira, Supra terram muscosam, loco subhumido umbroso, 4 February 1893, Malme 538 (holotype [S] S-R-4371 on-line image!, isotypes ILL-00009131 on-line image!, [S] S-07-12064 on-line image!) ( Fig. 5 )

= Peperomia arechavaletae A. C. P. de Candolle (1917: 466) var. arechavaletae , syn. nov. Type: — URUGUAY. Tacuarembó: Gruta de los Cuervos, Epiphyte, December 1902, Berro 1915 (lectotype (designated here) [G-DC] G-00317288 (two sheets) on-line image!, isolectotypes MVFA-0001045!, MVFA-0001046!). Syntypes: — URUGUAY. Tacuarembó: ad truncos ( Luehea divaricata Mart. et Zucc ), October 1894, Arechavaleta s.n. ([G-DC] G-00317286 on-line image!); BRAZIL. Brasilia: Glaziou 8943 ([G-DC] G00317287 on-line image!, isosyntypes B not seen, G00017074 on-line image!, [F] F0BN010830 on-line image!, P not seen).

– Peperomia arechavaletae var. minor auct. non Herter in Marchesi (1968: 10), p.p.

Herbs, epiphytic and epipetric, occasionally terrestrial. Stems erect or decumbent, angular, glabrous or with scarce minute trichomes, adventitious roots present in base and sometimes in basal nodes. Leaves 4–6 (7) verticillate; petiole 0.5–3 mm long, minutely hirtellous; leaf blade 1.1–2.6 × 0.6–1.4 cm, coriaceous, elliptic–rhombic to rhombic–obovate, 3–veined, veins markedly prominent abaxially, abaxial and adaxial surface glabrous, sometimes adaxial surface with scarce trichomes toward the base, margin without trichomes, base cuneate, apex acute to obtuse. Spikes 8–16 (–18) cm long, solitary, terminal, straight or slightly curved; peduncle 1.5–3.5 cm long, glabrous or with scarce minute trichomes; rachis 6–13 cm long, glabrous, smooth, loosely flowered; bracts 0.5–0.75 mm diam., circular or sub– triangular, margin entire. Fruits 0.75–1 mm long., globose–conic, sessile but on a pseudopedicel when mature, located in pits of the rachis, smooth, glabrous, pseudocupule viscose on the basal half.

Subgenus:— This species belongs to the subgenus Pseudocupula ( Frenzke et al. 2015) .

Distribution and habitat:— Argentina, Brazil, Paraguay and Uruguay. In the Southern Cone occurs in northeastern Argentina (Misiones), southern Brazil (Paraná, Rio Grande do Sul, Santa Catarina), central Paraguay (Presidente Hayes) and northeastern and eastern Uruguay (Cerro Largo, Rivera, Rocha, Tacuarembó, Treinta y Tres). Probably, in Uruguay this species also occurs in the southeast of Artigas, since it is close to the known distribution and has similar vegetation. The eastern Rocha department represents the southern limit of distribution for this species, such that San Miguel National Park is the southernmost locality where this species was registered ( Fig. 2A ). The species is common in moist hillside forests, often developing large clumps, on rocks, trunks or large branches.

Phenology:— Developing spikes were observed from May, flower anthesis from June to early December and mature fruits from November.

Conservation assessment:— This species was categorized in the AOO analysis as Near Threatened (NT) for Uruguay. Peperomia trineuroides has few records in the east of the country, which explains the category suggested for this species. It occurs in three protected areas: ‘Paisaje Protegido Quebrada de los Cuervos’, ‘Paisaje protegido Valle del Lunarejo’ and ‘Parque Nacional San Miguel’

Distinctive and field characters:— It is a sturdy herb with notoriously marked veins on both leaf surfaces. Within Uruguay Peperomia trineuroides differs from the other species of the genus by its verticillate leaves with glabrous margin and intermediate length leaf blades (less than 2.6 cm long). Alive this species is easily recognizable by its angular stems, which are commonly reddish. Mature fruits are brown and sticky.

Related taxa:— Peperomia trineuroides is closely related to P. trineura Miquel (1843: 175) , a species with smaller leaves, shorter spikes and a less sturdy habit. Both species inhabit similar environments and show an overlapping distribution. None of the herbarium specimens from Uruguay show the characteristics described for P. trineura , and so the species is considered absent from the country. Nevertheless, morphological differences between both species are weak and some herbarium specimens show intermediate characters ( Yuncker 1974). According to Monteiro & Guimarães (2008), accurate studies are necessary in order to elucidate their relationship.

Background in Uruguay:— The presence of this species in Uruguay was mentioned for the first time by Anne Casimir Pyramus de Candolle (1917) under Peperomia arechavaletae , in the original publication of the name. Later on, this name was cited by Trelease (1941), Trelease & Herter (1952) and Marchesi (1968).

Taxonomic observation:— The original description and the type materials of Peperomia arechavaletae agree with the characteristics given in the protologue and observed in the holotype of P. trineuroides , thus we include P. arechavaletae var. arechavaletae as a synonym of P. trineuroides .

Type observation I:— In the protologue of Peperomia arechavaletae three syntypes are mentioned: Arechavaleta s.n. (G-DC, on-line image!), Berro 1915 (G-DC, on-line image!), Glaziou 8943 (G-DC on-line image!). We designated Berro 1915 as the lectotype for P. arechavaletae , because it fits the diagnosis and is a complete specimen herbarium with developed spikes. Additionally, two duplicates are deposited in MVFA. The syntype Glaziou 8943 was deposited in Herb. Warm. according to the original publication of the species. Currently, this herbarium is included in C, where this sample was not found (Ib Friss com. pers.) but two presumed isosyntypes were found in F and G-DC, the latter with a Warming Herbarium label. In the absence of other evidence, we conclude that Glaziou 8943 (G-DC) must be the syntype.

Type observation II:—The type of Peperomia arechavaletae var. minor corresponds to P. tetraphylla . However, Marchesi (1968) applied this name to samples corresponding to different species. In this sense, Marchesi 1283 (MVFA) from Treinta y Tres ( Uruguay) belongs to P. trineuroides , and Rosengurtt & Del Puerto 8963 (MVFA) from Rio Grande do Sul ( Brazil) belongs to P. trineura .

Specimens examined:— URUGUAY. Cerro Largo: Sierra de los Ríos, [32º8’35’’S, 53º46’28’’W], February 1877, Arechavaleta 3000 (MVM). Rivera: Aº Rubio Chico , 31º7’56’’S, 55º54’47.8’’W, 12 April 2013, Mai et al. 307 (MVJB) ; Cultivated plant collected in Aº Rubio Chico , 31º7’56’’S, 55º54’47.8’’W, 8 September 2014, Mai 368 (MVJB) ; Cuchilla Negra, Bajada de Pena , 31º8’32’’S, 55º54’36’’W, 5 February 1989, Alonso Paz 569 (MVFQ). Rocha: Parque Nacional San Miguel, 33º42’49’’S, 53º34’41’’W, 13 October 2012, Rossado 6 (MVJB). Tacuarembó: Bañado de Rocha, Paso Lambaré, [31º31’44’’S, 55º57’25’’W], 28 March 1921, Osten 16070 (MVM) ; Gruta de los Cuervos , [31º36’S, 56º6’W], January 1908, Berro 4334 (MVFA) ; Gruta de los Cuervos , [31º36’S, 56º6’W], January 1940, Legrand 1891 (MVM) ; Gruta de los Cuervos , [31º36’S, 56º6’W], 3 January 1960, Rosengurtt B —7971 (MVFA) ; Gruta de los Cuervos , [31º36’S, 56º6’W], 7 December 1963, Arrillaga 1876 (MVFA) ; Rincón de Vassoura , 31º15’26.8’’S, 56º3’19’’W, 10 April 2013, Mai et al. 280 (MVJB) ; Sierra del Infiernillo, Estancia El Infiernillo, [31º23’56’’S, 56º7’18’’W], 4 November 1994, Bayce s.n. (MVFA 23924). Treinta y Tres: Quebrada de los Cuervos , [32º55’30’’S, 54º27’42’’W], 9April 1936, Legrand 693 (MVM) ; Quebrada de los Cuervos , [32º55’30’’S, 54º27’42’’W], 1 November 1964, Marchesi 1283 (MVFA) .

Additional specimens examined:— ARGENTINA. Misiones: Belgrano, Bdo. De Irigoyen , 26º16’4.1’’S, 53º39’24.5’’W, 820 m, 6 January 2011, Keller & Franco 9392 (CTES) ; Guaraní, Ruta 21 sobre puente Aº Fortaleza , [26º45’57’’S, 54º10’55’’W], 6 February 2011, Keller et al. 9604 (CTES) . BRAZIL. Rio Grande do Sul: Caçapava do Sul , [30º29’S, 53º29’W], 12 November 1980, Mattos 21883 (HAS) ; Caçapava do Sul, [30º29’S, 53º29’W], 12 November 1980, Mattos 21905 (HAS) ; Canela , [29º20’S, 50º49’W], 23 September 1997, Neves 2010 (HAS) ; Canela , [29º20’S, 50º49’W], 23 September 1997, Neves 2002 (HAS) ; Gramado, Parque Knorr , [29º22’S, 50º52’W], 9 January 1982, Krapovickas & Cristóbal 37601 (HAS) ; Pelotas na Estaçao experimental Florestal IBDF, 15 January 1981, Mattos et al. 22220 (HAS) ; São Jerónimo , [29º57’S, 51º42’W], 11 August 1986, Ramos 190 (HAS) ; São Francisco de Paula , [29º27’S, 50º34’W], 24 June 1998, Neves 2046–B (HAS) ; Santa Maria do Herval , [29º29’S, 50º59’W], 01 November 1989, Silveira 9270 (HAS) ; Veranópolis no Balneario do Retiro , [28º54’S, 51º34’W], 16 March 1984, Mattos & Mattos 25938 (HAS) ; Veranópolis no Balneario do Retiro , [28º54’S, 51º34’W], 28 July 1984, Silveira 1379 (HAS) ; Veranópolis no Balneario do Retiro , [28º54’S, 51º34’W], 1 August 1986, Silveira 3693 (HAS) .

Figures

FIGURE 1. Peperomia catharinae (A–B) and P. psilostachya (C–D). A. Habit. B. Detail of the spike with immature fruits. C. Habit. D. Detail of leaf margin. (A Mai et al. 51 (MVJB); B Mai et al. 33 (MVJB); C Mai et al. 347 (MVJB); D Mai & Rossado 298 (MVJB)). A–C drawn by Patricia Mai, D drawn by Andrés Rossado.

FIGURE 2. Geographic distribution of Peperomia species in Uruguay. A. Peperomia catharinae and P. trineuroides; location of Uruguay in South America B. P. comarapana and P. increscens. C. P. hispidula var. sellowiana and P. tetraphylla. D. P. pereskiifolia and P. psilostachya.

FIGURE 3. Peperomia comarapana (A–B) and P. increscens (C–E). A. Habit. B. Detail of the spike with flowers. C. Habit. D. Detail of the spike with mature fruit. E. Detail of a mature fruit. (A, B Rossado & Mai 350 (MVJB); C Mai & Delfino 369 (MVJB); D, E Mai & Gutiérrez 367 (MVJB)). A, C–E drawn by Patricia Mai, B drawn by Andrés Rossado.

FIGURE 4. Peperomia hispidula var. sellowiana (A–B) and P. tetraphylla (C–E).A. Habit. B. Detail of the leaf. C. Flowering branch. D. Detail of the spike with flowers. E. Detail of the spike with developing fruits. (A drawing adapted from Marchesi (1968) and Brussa et al. s.n. (MVJB 27795); B Brussa et al. s.n. (MVJB 27795); D Haretche 738 (MVJB); E Mai et al.1 (MVJB)). A–C drawn by Patricia Mai, D–E drawn by Andrés Rossado.

FIGURE 5. Peperomia pereskiifolia (A–B) and P. trineuroides (C–E). A. Flowering branch. c.s. Cross-section of the stem. B. Detail of the spike with flowers. C. Flowering branch. c.s. Cross-section of the stem. D. Detail of the spike with flowers. E. Detail of mature fruit with basal pseudocupule. (A, B Rossado & Mai 354 (MVJB); C, D Mai 368 (MVJB); E Mai et al. 307 (MVJB)).A, C, D drawn by Patricia Mai, B, E drawn by Andrés Rossado.