Tradescantia fluminensis Vell., Fl. Flumin.: 140. 1829.

Pellegrini, Marco O. O., 2018, Wandering throughout South America: Taxonomic revision of Tradescantia subg. Austrotradescantia (D. R. Hunt) M. Pell. (Commelinaceae), PhytoKeys 101, pp. 1-97 : 23-29

7. Tradescantia fluminensis Vell., Fl. Flumin.: 140. 1829. Figs 20 , 21

Tradescantia albiflora Kunth, Enum. Pl. 4: 84. 1843. Lectotype (designated here). s.loc., cultivated in Germany, Horto Berolinense, fl., s.dat., C.S. Kunth 165 (B barcode B100264915!; isolectotype: B barcode B100264916!).

Tradescantia fluminensis f. albovittata (Pynaert) Voss in Siebert & Voss, Vilm. Blumengärtn. ed. 3, 1: 1144. 1895. Syn. nov.

Tradescantia albovittata Pynaert in Burvenich et al., Rev. Hort. Belge Étrangère (Eds Burvenich et al.) 11: 205. 1885. Lectotype (designated here). [illustration] Original chromolithograph at the Bureau de la Revue, Ghent, and later published in Burvenich et al., Rev. Hort. Belge Étrangère 11: t. 16. 1885. Syn. nov.

Tradescantia fluminensis f. aureovittata Voss in Siebert & Voss, Vilm. Blumengärtn. ed. 3, 1: 1143. 1895. Type. not found. Syn. nov.

Tradescantia laekenensis L.H.Bailey & E.Z.Bailey, Hortus: 616. 1930, nom. nud.

Tradescantia striata L.H.Bailey & E.Z.Bailey, Hortus: 616. 1930, nom. nud.

Type material.

Lectotype (designated by Pellegrini et al. 2015). [illustration] Original parchment plate of " Flora Tradescantia fluminensis " in the Manuscript Section of the Biblioteca Nacional of Rio de Janeiro [cat. no.: mss1198652_156] and later published in Vellozo, Fl. Flumin. Icones 3: t. 152. 1831.

Description.

Herbs ca. 15-50 cm tall, with an indefinite base, terrestrial, rupicolous or epiphytes. Stems prostrate with ascending apex, delicate to slightly succulent, little to densely branched; internodes 1.6-9 cm long at base, distally shorter, medium to dark green, glabrous, with a leaf-opposed longitudinal line of short, uniseriate, hyaline hairs in the terminal portion of the stems. Leaves distichously-alternate, subpetiolate; ptyxis involute; sheaths 0.2-1.3 cm long, medium green, glabrous, margin densely setose, hairs hyaline to light brown; petiole 0.2-1.5 cm long to indistinct; blades (1.3-1.6-)2.2-11.8 × (0.6-0.8-)1.1-4.8 cm, elliptic to broadly elliptic or ovate to broadly ovate, flat, membranous to slightly succulent, glabrous on both sides, adaxially dark to medium green, abaxially light to medium green, turning olive-green or medium to dark brown when dry, base cordate to obtuse, rarely cuneate, margin green, ciliolate, flat, apex acute; midvein conspicuous, adaxially impressed, secondary veins conspicuous, adaxially impressed, abaxially conspicuous, becoming more evident on both sides when dry. Synflorescences terminal or axillar in the distal portion of the stems, composed of a solitary main florescence, 1 per leaf axis. Inflorescences (main florescences) consisting of a pedunculate double-cincinni fused back to back; peduncles 0.6-4.7 cm long, dark to medium green, glabrous to sparsely pilose near the cincinni bracts, with a longitudinal line of short, uniseriate, hyaline hairs, opposed to the first cincinni bract; cincinni bracts 1.1-5.7 × 0.5-2.6 cm, similar to each other, ovate to broadly ovate, leaf-like, glabrous, medium to dark green, abaxially light to medium green, base cordate to obtuse, saccate, margin ciliolate, sometimes sparsely setose at base, flat, apex acute; double cincinni (4-)6-12-flowered. Flowers 1.5-2 cm diam., pedicels 0.6-1.5 cm long, medium green, glabrous to distally sparsely glandular-pubescent, hairs hyaline; floral buds ovoid; sepals 4.6-6.7 × 2.6-4.4 mm, dorsally keeled, medium green, pilose along the keel; petals 0.7-1 × 0.4-0.6 mm, plicate, white; filaments 5-5.2 mm long, anthers 0.8-1 × 0.9-1 mm; ovary 1-2.1 × 0.9-1.3 mm, style 3.5-4.4 mm long; pistil the same length as the stamens. Capsules 3.3-4.1 × 2.7-2.9 cm. Seeds 1.4-1.6 × 1.1-1.2 mm, testa brown to greyish-brown, not cleft towards the embryotega, costate; hilum equal ½ the length of the seed.

Examined material.

ARGENTINA. Buenos Aires: Berazategui, Conchitas, fl., Dec 1919, A. Castellanos 794 (BA); La Plata, fl., 18 Oct 1928, A.L. Cabrera 441 (LP); fl., 15 Oct 1941, A.L. Cabrera 9796 (LP). Chaco: 1° de Mayo, Colonia Benítez, fl., 9 Oct 1970, A.G. Schulz 17677 (CORD, CTES, SI). Córdoba: Córdoba, fl., 24 Oct 1902, T.J.V. Stuckert 11937 (CORD); fl., 25 Nov 1902, T.J.V. Stuckert 12151 (CORD); Punilla, Capilla del Monte, en las proximidades del Cerro El Zapato, fl., 30 May 1955, M.M. Job s.n. (BA no. 29081). Corrientes: Mercedes, Macrosistema Ibera, Estancia Rincon del Diablo, fl., 28 Aug 1998, M.M. Arbo et al. 8010 (CORD, CTES); Santo Tomé, Garruchos, destacamento de Prefectura a orillas del Río Uruguay, fl., 6 Sep 1993, M.M. Arbo et al. 5826 (CTES). Misiones: Cainguás, Predio UNLP Reserva Privada Valle del Arroyo Cuña Pirú, márgenes del arroyo Cuña Pirú, cerca del balneário, fl., 14 Mar 2000, F. Biganzoli et al. 800 (CORD); Candelaria, Bonpland, fl., Oct 1906, H. Van de Venne 67 (BA); Guaraní, Ruta Nacional 14, Km 315, camino de San Vicente a San Pedro, desvío hacia el obraje de M. Carré, 13 km de R-14, fl., 13 Feb 1996, O. Morrone et al. 747 (CORD); San Ignacio, Teyucuaré, Peñón Reina Victoria, fl., 25 Sep 1972, A. Schinini 5603 (CORD); San Pedro, Parque Provincial Cruce Caballero, picada al NW, fl., 23 Sep 1997, F.O. Zuloaga & O. Morrone 6478 (CORD). Santa Fe: Santa Fe, fl., 1 Sep 1984, A. Gagneten 25 (CORD). BRAZIL. Espírito Santo: Aracruz, Guaraná, près Ribeirão do Meio, fl., 30 Jul 1993, M. Pignal H310 (BAH, P); Castelo, Parque Estadual do Forno Grande, fl., 1 Nov 2004, L. Kollmann 7221 (MBML); trilha para o Forninho, fl., 15 Oct 2008, R.C. Forzza et al. 5334 (CEPEC, MBML, RB, UPCB); Vargem Alta, fl., 2 Sep 1946, A.C. Brade 19416 (RB); Domingos Martins, between São Pedro de Urânia and Pedra Azul, fl., 31 Jul 1986, T.B. Croat 61837 (MO, R); Santa Maria de Jequitibá, Pedra do Garrafão, fl., 23 Aug 2015, M.C. Almeida 121 (R). Minas Gerais: Caeté, alto da Serra da Piedade, fl., 9 Nov 2002, J.A. Lombardi 4933 (HRCB, US); Caldas, Serra de São Domingos, fl., 28 Feb 2013, M.O.O. Pellegrini & J.F. Barbosa 321 (RB); Tiradentes, Serra de São José, fl., fr., 3 Oct 1987, M. Peron 358 (RB). Paraná: Carambeí, Catanduva de Fora, fl., 25 Aug 2013, M.E. Engels 1469 (ALCB, FURB, HCF, JOI, MBM, RB, UNOP, UPCB); Catanduvas, Barra do Guarani, fl., 10 Oct 1974, G. Hatschbach & P. Pelanda 35124 (K, MBM); Curitiba, Parque Barigui, fl., fr., 10 Nov 1970, L.T. Drombowski & Y.S. Kuniyoshi 3069 (MBM, US); fl., 18 Nov 197, R. Kummrow 107 (K, MBM); Campina do Siqueira, fl., 20 Nov 1966, C. Stellfeld 1643 (UPCB, US); Jardim Botânico de Curitiba, fl., 26 Aug 1993, J. Cordeiro & J.M. Silva 1092 (FLOR, MBM, UEC, US); fl., 24 Sep 2014, M.O.O. Pellegrini et al. 407 (US); Parque Municipal Capão da Embuia, fl., 25 Sep 2014, M.O.O. Pellegrini et al. 410 (RB); Itapecerica da Serra, Aldeinha, BR-116, km 299, fl., fr., 5 Oct 1998, L.N. Hara s.n. (FUEL no. 29803); Mariópolis, rodovia Pato Branco-Palmas, km 205, fl., 21 Nov 1999, D.C. Rocha s.n. (BOTU no. 23008); Palmeira, fl., s.dat., T.A. Preston s.n. (K barcode K001248126); São José dos Pinhais, Caminho do Vinho, área de plantação de agrião, fl., fr., 25 Sep 2014, M.O.O. Pellegrini et al. 413 (RB). Rio de Janeiro: s.loc., fl., fr., s.dat., G. Gardner s.n. (K barcode K001248117); fl., s.dat., C. Gaudichaud 340 (P); fl., s.dat., J. Miers 3031 (K); fl., fr., s.dat., F. Sellow 186 (K); environs de Rio de Janeiro, fl., 1843, M. Weddel 180 (P); fl., fr., 1843, M. Weddel 595 (P); fl., 1843, M. Weddel 598 (P); Guapimirim, Granja Monte Olivete, margem do Rio Bananal, fl., 17 Nov 1993, J.M.A. Braga et al. 844 (RB); Rio Bananal, fl., fr., 16 Aug 1995, J.A. Lira Neto et al. 94 (RB); Mangaratiba, Reserva Ecológica do Rio das Pedras, próximo ao poço do Rio Grande, fl., fr., 31 Nov 1996, J.A. Lira Neto et al. 472 (RB); Nova Friburgo, Morro da Caledônia, fl., fr., 8 Jun 1977, G. Martinelli et al. 2465 (RB); Macaé de Cima, Fazenda Ouro Verde, fl., 30 Jul 1994, C.M. Vieira et al. 610 (RB); fl., 26 Jan 2012, M.O.O. Pellegrini et al. 208 (RB); Mury, Cachoeira do Rio das Flores, fl., fr., 24 Jul 1986, M. Leitman 135 (RB); fl., 10 Oct 2004, A.F.P. Machado 363 (RB, SPF); Petrópolis, fl., s.dat., T.A. Preston s.n. (K barcode K001248127); prope Petrópolis, fl., fr., 10-16 Jul 1882, J. Bal s.n. (K barcode K001248130); Cascatinha, fl., fr., 18 Jul 1943, O.C. Goés & D. Constantino 348 (RB); fl., fr., Jul 1944, O.C. Goés & E. Dionisio 797 (RB); Estrada da Saudade, Morro Seco, fl., fr., Dec 1943, O.C. Goés & E. Constantino 920 (RB); fl., Castelânea, 8 Sep 2010, M.O.O. Pellegrini 48 (RB, RFA); Resende, Parque Nacional do Itatiaia, margem do Rio Campo Belo, perto do lote 17, fl., 17 Oct 1977, V.F. Ferreira & Briolanjo 136 (RB); Rio Claro, Lídice, Parque Estadual Cunhambebe, caminho para o Alto da Serra, 7 Aug 2013, fl., fr., B.C. Bandeira et al. 256 (RB); Rio de Janeiro, Serra do Andaraí, fl., 19 Dec 1946, L.E. Mello-Filho 529 (R); Tijuca, caminho do Morro do Archer, fl., fr., 10 Nov 1948, A.C. Brade et al. s.n. (RB no. 65375); Parque Nacional da Tijuca, fl., fr., 27 Oct 1995, M.G. Bovini et al. 899 (RB); Corcovado, fl., fr., 1837, G. Gardner 135 (K, P); Paineiras, fl., fr., 5 Oct 1879, R. Galvão 143 (P); trilha para o Morro da Cocanha, Alto da Boa Vista, fl., fr., 16 Jan 1994, J.M.A. Braga & R. Neves 943 (RB); fl., 1 Nov 1996, J.M.A. Braga 3647 (RB); Vargem Grande, Morro do Manga Larga, fl., fr., 2 Dec 1995, C.M. Vieira et al. 758 (RB); Santa Maria Madalena, fl., fr., s.dat., A. Lisbôa s.n. (RB no. 2653); Fazenda da Boa Fé, fl., 11 Sep 1942, L.E. Mello-Filho 88 (R); Mata do Garrafão, fl., May 1917, A. Sampaio 2655 (R); Parque Nacional da Serra dos Órgãos, Trilha Suspensa, fl., 23 Sep 2011, C.P. Bruniera et al. 385 (RB, SPFR); fl., 22 Oct 2012, D.O. Dinato et al. 11 (HRCB, UPCB); Praça da Barragem, fl., 12 Sep 2014, L.S.B. Calazans et al. 448 (RB); Venda Nova, fl., 22 Aug 2004, C.H.R. Paula 650 (RB). Rio Grande do Sul: Arroio do Ouro, Vale Real, fl., 31 Aug 1998, S. Diesel 1521 (US); Cachoeira do Sul, Fazenda São Carlos, fl., Sep 1987, N. Silveira & J. Mattos 6681 (HAS); Canela, fl., 10 Nov 2006, M.L. Guedes 12706 (ALCB); Erehim, campus da Uri, fl., 21 Oct 1993, A. Butzke 10824 (US); Esteio, prope Porte Alegre, fl., fr., 24 Nov 1948, B. Rambo 38326 (HBR); Centro dos Trabalhadores, fl., Nov 1974, M.L. Porto & L. Aguiar s.n. (HAS no. 1533); Farroupilha, fl., 26 Oct 1956, O.R. Camargo 885 (PACA); Montenegro, Pareci, fl., 10 Oct 1945, E. Henz s.n. (PACA no. 32711); fl., 17 Aug 1949, B. Rambo 43004 (K, LIL, PACA); Porto Alegre, fl., s.dat., O.R. Camargo 2454 (PACA); Morro do Sabiá, fl., 5 Oct 1949, B. Rambo 43764 (K, LIL, PACA); Vila Manresa, fl., 27 Nov 1945, B. Rambo 30667 (K, PACA); Reserva Biológica do Lami, fl., Sep 2003, A.S. Mello & D. Fuhro s.n. (HAS no. 45477); São Francisco de Paula, Cambara, fl., fr., Feb 1948, R. Rambo 36590 (PACA); São Leopoldo, fl., 1907, F. Theissen s.n. (PACA no. 25293); Silveira Martins, fl., 6 Oct 2011, G.A. Dettke & J. Durigon 959 (ICN); Taquarí, Estação Experimental de Pomicultura, fl., 8 Nov 1958, O.R. Camargo 3319 (PACA); Triúnfo, Bom Jardim, CMN 7, fl., Aug 1977, I. Ungaretti 532 (HAS); Viamão, bairro Tarumã, região do entorno do Lago Tarumã, fl., s.dat., P.J.S. Silva Filho 1597 (ICN). Santa Catarina: Bocaina do Sul, Pessegueiros, fl., 8 Nov 2010, G.A. Dettke 476 (ICN); Bom Jardim da Serra, Serra do Rio do Rastro, fl., s.dat., M. Sobral et al. 9019 (ICN); Ibirama, fl., 20 Oct 1953, R.M. Klein 614 (HBR); Itapiranga, proximidades do Rio Uruguai, fl., 6 Feb 1951, B. Rambo 49832 (PACA); Rodeio, fl., 19 Oct 2015, L.A. Funez 4550 (FURB); São Bento do Sul, Trilha do Parque Florestal do SAMAE, pequeno remanescente de mata próximo a estrada, fl., 28 Sep 2014, M.O.O. Pellegrini & P. Schwirkowski 420 (RB); São Francisco do Sul, fl., 13 Oct 2008, T.G. Fendrich 7136 (HUFSJ, JOI); Timbó, Centro, margem do Rio dos Cedros, fl., 11 Oct 2014, L.A. Funez 3558 (FURB); Turvo, Arar, 20.x.1943, fl., R. Reitz 73 (HBR, RB). São Paulo: s.loc., fl., Aug 1942, s.leg. s.n. (CESJ no. 812, HAS no. 67752); Biritiba Mirim, Estação Biológica de Boracéia, fl., 29 Sep 1983, A. Custódio Filho 1568 (RB, SP); Campinas, Fazenda Santa Eliza, Mon jolinho, fl., 9 Sep 2004, J.L.M. Aranha Filho et al. 26 (UEC); Cunha, fl., 7 Sep 2015, A. Maruyama & L. Cicco 40 (SPSF); fl., 12 Oct 2015, A. Maruyama & L. Cicco 134 (SPSF); fl., 12 Oct 2015, A. Maruyama & L. Cicco 151 (SPSF); Reserva Estadual de Cunha, Instituto Florestal, Secretaria de Agricultura, fl., fr., 20 Nov 1979, A. Fonseca Vaz 294 (RADAM, RB); Itapeva, rodovia Francisco Alves Negrão, SP-258, entre Itapeva-Itararé, km 289, fl., 23 Oct 2007, R.C. Forzza et al. 4765 (CEPEC, RB, SPF); Santo André, Reserva Biológica do Alto da Serra de Paranapiacaba, fl., 11 Oct 2006, M. Kirizawa 3550 (RB, SP); São Paulo, Butantã, fl., 16 Sep 1919, F.C. Hoehne s.n. (SP no. 3414); Mandaqui, fl., May 1913, Toledo 637 (RB); Jardim Botânico e Parque do estado, fl., 12 Aug 1968, T. Sendulksy 981 (RB, SP); mata do Instituto de Botânica de São Paulo, fl., 22 Nov 1976, F.S. Cavalcante & I.T. Menezes 5 (RB, SP); arredores do Castelinho do Instituto de Botânica de São Paulo, fl., 21 Nov 1980, N.A. Rosa & J.M. Pires 3824 (INPA, K); fl., 14 Oct 1982, M.C.B. Attié et al. 52 (RB, SP); Reserva da Cidade Universitária Armando de Salles Oliveira, fl., 18 Aug 1998, M. Groppo Jr. 345 (SP, SPF); Reserva Biológica do Parque Estadual das Fontes do Ipiranga, fl., 20 Apr 1979, M. Kirizawa 418 (RB, SP); fl., 20 Jun 1979, M. Kirizawa 419 (RB, SP); fl., 25 Jun 1979, J.A. Correa 94 (RB, SP); fl., 9 Sep 1980, M.G.L. Wanderley 138 (RB, SP); fl., 1 Sep 1982, R.D. Marassi 5 (K, RB, SP). PARAGUAY. Itapúa: Isla Yacyretá, Zona de transición, extremo de dunas, fl., 14 Aug 1992, A.B. Pin 207 (CORD, CTES). URUGUAY. Without province: s.loc., fl., 23 Feb 1912, P. Serre s.n. (P barcode P01639779). Canelones: Santa Lucia, fl., 14 Nov 1922, H.M. Smith 63 (US). Montevideo: s.loc., fl., s.dat., J. Tweedie s.n. (K); Malvin, fl., s.dat., F. Felippone 4565 (CORD); Nico Perez, fl., 25 Nov 1947, W.G.F. Herter 436d (SI, US); Peniarolli, fl., Oct 1926, W.G.F. Herter 436a (P).

Distribution and habitat.

Argentina and Brazil (states of Espírito Santo, Rio de Janeiro, Minas Gerais, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul), Paraguay and Uruguay; in the Atlantic Forest, Cerrado, Chaco and Pampa domains (Fig. 21 ). It can be found growing as terrestrial or epiphyte understorey in shaded moist forests, as a weed and at roadsides.

Phenology.

It was found in bloom throughout the year but peaking during the rainy season and being less commonly in bloom during the dry season. Fruiting seems to be uncommon, with most fruiting specimens recorded in the state of Rio de Janeiro, Brazil.

Etymology.

The epithet " fluminensis " makes reference to the region the species was originally described, the state of Rio de Janeiro.

Conservation status.

Tradescantia fluminensis possesses a wide EOO (ca. 1,440,097.589 km2), being also an aggressive weed worldwide known to occur in Australia, Bermuda, Italy, Japan, Kenya, New Zealand, Portugal, Puerto Rico, Russia, Saint Lucia, South Africa, Swaziland and USA. (Hunt 2001; Burns 2008; Fowler et al. 2013; GSID 2015; pers. observ.). Thus, following the IUCN recommendations ( IUCN 2001), it should be considered Least Concern (LC).

Nomenclatural notes.

Tradescantia fluminensis was, together with T. geniculata Vell. (≡ T. cymbispatha ), the first two species currently placed in T. subg. Austrotradescantia to be described ( Vellozo 1829, 1831). They were both described in the infamous Florae fluminensis by Friar José Mariano da Conceição Vellozo, based on specimens collected by him in the state of Rio de Janeiro ( Pellegrini et al. 2015).

When describing T. albovittata , Pynaert (in Burvenich et al. 1885) makes no reference to any herbarium specimen. Nonetheless, the author presents a gorgeous chromolithograph that shows the habit of the plant and its characteristic white-striped leaves. Thus, I designate the original illustration as the lectotype of T. albovittata and reduce it to a synonym of T. fluminensis .

According to Stafleu and Cowan (1986), it is unknown where the specimens of any names described by A. Voss are housed. Voss (in Siebert and Voss 1895), makes no reference to any kind of studied specimen and presents no illustration for most of his names, which prevents the designation of lectotypes. Since no specimens matching the diagnosis of T. fluminensis f. aureovittata were located, I was unable to designate neotypes for it.

Comments.

The name T. fluminensis has been misapplied to almost all species of T. subg. Austrotradescantia , even to species from the T. crassula group. Here I consider T. fluminensis as a much lesser variable entity than accepted by previous authors (e.g. Seubert 1871; Clarke 1881; Hunt 1980). Tradescantia fluminensis is morphologically similar to T. cymbispatha , T. chrysophylla , T. hertweckii , T. mundula and T. umbraculifera due to their indefinite base, prostrate stems with ascending apex (Fig. 20A ), involute ptyxis, saccate cincinni bracts (Fig. 20D ), white petals (Fig. 20D, F ), seeds with uncleft testa towards the embryotega and hilum ½ the length of the seed (Fig. 20G ). It can be easily differentiated from T. cymbispatha and T. chrysophylla by its subpetiolate leaves with impressed secondary veins (vs. sessile leaves with inconspicuous secondary veins, in T. cymbispatha and T. chrysophylla ), blades glabrous or unevenly covered by indumentum (vs. evenly covered by indumentum) and sepals dorsally keeled (vs. sepals without dorsal keels). It is morphologically more closely related to T. hertweckii , T. mundula and T. umbraculifera due to their leaves with impressed secondary veins, dorsally keeled sepals and petals always white. Tradescantia fluminensis can be differentiated from T. mundula due to its glabrous stems (vs. strigose in T. mundula ), leaves glabrous (vs. unevenly to evenly strigose), blades membranous to slightly succulent and abaxially light to medium green (vs. chartaceous and abaxially completely to partially vinaceous), sepals pilose with hairs restricted to the keels (vs. evenly velutine) and plicate petals (vs. flat). Tradescantia fluminensis can be differentiated from T. umbraculifera due to its subpetiolate leaves (vs. sessile in T. umbraculifera ), leaf-like cincinni bracts (vs. spathaceous), pedicels green at anthesis (vs. white), petals plicate (vs. flat) and pistil as long as the stamens (vs. longer than the stamens). Tradescantia fluminensis is easily identified in the field, due to its emerald green and glossy leaves, that give healthy plants a characteristic plastic aspect.

As aforementioned, T. fluminensis is a popular potted plant, as well as an aggressive weed worldwide. However, many cultivated specimens or weedy populations studied by me actually represent other species from T. subg. Austrotradescantia . In cultivation, many plants are referred to as T. albiflora Kunth, which is here kept as a synonym of T. fluminensis . Nonetheless, they actually represent specimens of T. mundula and, more rarely, specimens of T. cymbispatha and T. crassula . Alternatively, the only other species of T. subg. Austrotradescantia known to me to have been introduced in cultivation is the pink and lilac flowered forms of T. cerinthoides , generally treated by gardeners as T. blossfeldiana . In cultivation, T. fluminensis rarely set seeds and commonly reproduces itself by stem fragmentation. Seed production seems to be also uncommon throughout most of its native range, being only recurrently observed in the state of Rio de Janeiro, Brazil. The reason for this is unknown, since all observed native populations and all specimens kept in cultivation were consistently seen being visited by several insects. My hypothesis is that T. fluminensis actually represents a self-incompatible species and thus some subpopulations are incapable of producing seeds, since they might be exclusively composed of clonal individuals. I believe that, in light of the present taxonomic revision, the reproductive biology of T. subg. Austrotradescantia , especially of the T. fluminensis group, should be properly studied.

Figures

Figure 20. Tradescantia fluminensis Vell. A habit, showing the mat-forming prostrate stems B detail of the stem and leaf-sheath, showing the setose margin of the leaf-sheath and the subpetiole C adaxial side of the leaf-blade, showing the impressed secondary veins D detail of the inflorescence, showing the saccate cincinni bract base, the plicate petals and the pistil as long as the stamens E floral bud, showing the dorsally keeled sepals and the pilose indumentum restricted to the keels F front view of a flower, showing the plicate petals G dorsal and ventral views of the seed, showing the costate testa not cleft towards the embryotega and the hilum ca. 1 / 2 the length of the seed. Photos by M. O. O. Pellegrini.

Figure 21. Distribution of Tradescantia fluminensis Vell. Light green- Amazon Forest; Orange- Cerrado; Red- Caatinga; Yellow- Chaco and Pantanal; Olive-green- Pampa; Dark green- Atlantic Forest; Purple- Andean Yungas.