Tradescantia tenella Kunth, Enum. Pl. 4: 83. 1843.

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 : 40-44

11. Tradescantia tenella Kunth, Enum. Pl. 4: 83. 1843. Figs 28 , 29

Tradescantia fluminensis f. tenella (Kunth) Voss in Siebert and Voss, Vilm. Blumengärtn. ed. 3 1: 1143. 1895.

Tradescantia fluminensis var. tenella (Kunth) C.B.Clarke in De Candolle & De Candolle, Monogr. Phan. 3: 295. 1881. Holotype. URUGUAY. Montevideo, fl., fr., Dec 1836, F. Sellow d2290 (B barcode B100247280!).

Tradescantia anagallidea Seub. in Martius, Fl. bras. 3(1): 249. 1871. Lectotype (designated here). BRAZIL. s.loc., fl., fr., s.dat., F. Sellow 2801-67 (B barcode B100247281!; isolectotypes: IPA no. 54001!, MO barcode MO3020446!). Syn. nov.

Description.

Herbs ca. 5-50 cm tall, with a definite base, terrestrial, rupicolous or epiphytes. Stems erect, succulent, densely branched to fruticose; internodes 1.5-9.2 cm long at base, distally shorter, light to medium green to vinaceous, glabrous, sometimes glandular-pubescent or sparsely hirsute or a mixture of glandular and eglandular hairs, with a leaf-opposed longitudinal line of short, uniseriate, hyaline hairs in the terminal portion of the stems. Leaves distichously-alternate, sessile to subpetiolate; ptyxis involute; sheaths 0.3-1.3 cm long, light to medium green, glabrous to hirsute, margin densely setose, hairs hyaline to light brown; petiole 0.2-2.4 cm long to indistinct; blades (0.5-0.9-)1.2-14.8 × 0.5-3.6 cm, ovate to broadly ovate, rarely elliptic to lanceolate, flat, membranous to chartaceous, glabrous to sparsely hirsute on both sides, adaxially light to medium to dark green, sometimes with a vinaceous stripe along the midvein, abaxially light to medium green or vinaceous, turning olive-green to greyish-green when dry, base cordate to obtuse, rarely cuneate, margins green, ciliolate, slightly revolute, apex acute to acuminate; 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 1.9-5.3(-9.3) cm long, light to medium to dark green or vinaceous, glabrous, sometimes glandular-pubescent or sparsely hirsute, with a dense longitudinal line of short, uniseriate, hyaline to light brown hairs; cincinni bracts 0.4-8.1 × 0.2-3.1 cm, unequal to strongly unequal to each other, elliptic to ovate to broadly ovate, leaf-like, glabrous to sparsely hirsute, light to medium to dark green, sometimes with a vinaceous stripe along the midvein, abaxially light to medium green or vinaceous, base cordate to obtuse, saccate, margin ciliolate, slightly revolute, apex acute; double cincinni (4-)8-14-flowered. Flowers 0.4-1.0 cm diam., pedicels 0.4-1.7 cm long, green to vinaceous, sparsely glandular-pubescent to glandular-pubescent; floral buds ovoid; sepals 3-6.6 × 1.8-2.5 mm, dorsally keeled, green, sparsely glandular-pubescent to glandular-pubescent, rarely glabrous, hairs hyaline; petals 3.5-6.8 × 4-5.1 mm, white to white with pink apex to light pink to pink; filaments 3.8-4.1 mm long, anthers 0.9-1.1 × 1.2-1.8 mm; ovary 1.6-1.8 × 1.1-1.4 cm, style 3.5-3.8 mm long; pistil the same length as the stamens. Capsules 2.6-4.5 × 2.2-2.5 cm. Seeds 0.9-1.7 × 0.9-1.5 mm, testa grey to greyish-brown, not cleft towards the embryotega, rugose; hilum shorter than ½ the length of the seed.

Specimens seen.

ARGENTINA. Buenos Aires: Isla Martín García, fl., fr., 21 Oct 1992, J. Hurrell et al. 1244 (LP, MBM); Reserva Natural y Sitio Histórico Isla Martín García, fl., 30 Oct 2004, S. Torres Robles et al. 1987 (LP, US). Corrientes: s.loc., fl., fr., s.dat., A.J.A. Bonpland s.n. (P barcode P02173872); Capital, Corrientes, invernáculo del Instituto de Botánica del Nordeste, Facultad de Ciencias Agrarias, fl., fr., 10 Sep 2002, G. Seijo 2889 (CTES); Estancia, Santa Teresa, fr., 22 Oct 1949, T.M. Pedersen 440 (C, K, U, US); San Martín, Tres Cerros, Co. Capará, fl., fr., 15 Sep 1979, A. Schinini et al. 18456 (CORD, CTES); Sauce, 25 km SW de Sauce, ruta 126, fl., fr., 20 Oct 1977, O. Ahumada et al. 1174 (CTES). Chaco: Colonia Benítez, fl., 18 Sep 1942, A. Schinini 3539 (CORD, CTES). Misiones: Apostoles, San José, fl., fr., 14 Oct 1978, S.A. Renvoize 3090 (CORD, K, P, U, US, WAG); Cainguás, Salto del Tabay, fl., 12 Oct 1975, E.M. Zardini et al. 789b (LP, MO); Salto Golondrina, sobre Arroyo Guiray, fl., 8 Nov 2000, M.E. Múlgura et al. 2447 (CORD, SI); Candelaria, Santa Ana, fl., fr., 25 Nov 1945, J.E. Montes 1127 (K, LIL); Profundidad, fl., 19 Sep 1974, A. Krapovickas et al. 25712 (CORD, CTES); Iguazú, Puerto Istueta, fl., 27 Sep 1950, J.E. Montes 10201 (CORD, CTES, LIL); Parque Nacional do Iguazú, Sendero frente a Isla San Martín, fl., fr., 10 Aug 1995, R. Vanni et al. 4221 (CORD, CTES); Oberá, Salto Teodoro Cuenca, fl., 23 Sep 2000, M.E. Múlgura et al. 2282 (CORD, SI); Río Iguazú, fl., Sep 1900, G.E. Gerling s.n. (BA no. 16402); San Ignacio, San Ignacio, 3 a 5 km camino a Teyucuaré, fl., fr., 8 Nov 1913, M.N. Correa et al. 5371 (BAB, CTES, SI); San Pedro, Moconá, Prefectura Nacional Pepirí Mini, fl., 13 Oct 2003, D. Hojsgaard 307 (CTES, MNES). Santa Fe: Vera, campo de pruebas, FUNDAPAZ, fl., 11 Nov 2003, G. Marino 1906 (BA); próximo a La Gallareta, fl., 8 Jan 1997, J.F. Pensiero et al. 5215 (BA). BRAZIL. Paraná: Curitiba, Vila Nova, fl., fr., 21 Nov 1972, P. Occhioni 5238 (RFA); Foz do Iguaçú, fl., s.dat., J.G. Kuhlmann s.n. (RB no. 166655); fl., 7 Nov 1969, L.T. Dombrowski 2964 (MBM, US); Parque Nacional do Iguaçú, Cataratas do Iguaçú, fl., 27 Sep 1967, O. Boelcke 13449 (CORD, CTES); fl., 27 Sep 1967, A. Krapovickas 13373 (CTES); fl., 12 Aug 1969, G. Hatschbach 23166 (MBM, US); fl., 21 Aug 1985, G. Hatschbach & A.C. Cervi 49559 (MBM, UB, US); margem do Rio Iguaçú, abaixo das cataratas, próximo a administração do parque, fl., fr., 8 Oct 2012, R.C. Forzza et al. 7379 (RB, UPCB); Mangueirinha, Rio Iguaçú, Porto Fanor, fl., 20 Oct 1966, G. Hatschbach 15172 (MBM, NY, P, US, WAG); Morretes, Parque Estadual Pico do Marumbi, trilha de acesso ao Morro do Falcãozinho, fl., 19 Sep 1999, C. Kozera 1216 (UPCB); Guarapuava, Águas Santa Clara, fl., 1 Oct 1986, G. Hatschbach 50570 (MBM, US); Rio do Cedro, fl., 19 Oct 1967, G. Hatschbach 17490 (MBM, US); Morretes, Cadeado, fl., 14 Sep 1966, G. Hatschbach & A.O. Guimarães 14721 (MBM, US); Paranaguá, Porto Dom Pedro II, fl., fr., 26 Feb 1911, P. Dusén (NY, S); São José dos Pinhais, Serra dos Castelhanos, fl., 6 Nov 2004, A. Dunaiski Jr. 2595 (MBM); Serra do Mar, Desvio Ypiranga ad viam ferream, fl., fr., 23 Aug 1914, G. Jansson 885a (NY, S); Telêmaco Borba, Fazenda Monte Alegre, beira do Ribeirão Varanal, ponto 2, fl., 14 Oct 2004, T.I.N. Azevedo 6 (FUEL); fl., fr., 28 Aug 2006, T.I.N. Azevedo & S.I. Azevedo 400 (FUEL); fl., fr., 29 Aug 2006, T.I.N. Azevedo & S.I. Azevedo 433 (FUEL); margem da nascente do Ribeirão Varanal, fl., fr., 11 Nov 2005, T.I.N. Azevedo et al. 284 (FUEL); ponto médio do Ribeirão Varanal, fl., fr., 14 Oct 2004, T.I.N. Azevedo 7 (FUEL); fl., fr., 19 Jul 2005, T.I.N. Azevedo & J. Carneiro 151 (FUEL); fl., fr., 10 Nov 2005, T.I.N. Azevedo et al. 240 (FUEL); fl., 10 Nov 2015, T.I.N. Azevedo et al. 256 (FUEL). Rio Grande do Sul: Bom Jesus, Fazenda Bom Jardim, fl., 15 Nov 2003, R.A. Wasum & J. Bordin 2051 (HUCS, US); Caçapava do Sul, Guaritas, fl., fr., Sep 1985, M. Sobral & C. Grabauska 4291 (ICN, K); fl., fr., Sep 1985, M. Sobral & C. Grabauska 4295 (ICN, K); Camaquã, rodovia Dom Feliciano, fl., Nov 1978, J. Mattos et al. 19979 (HAS); Cambará do Sul, nos arredores de Ouro Verde, fl., Dec 1977, O.R. Camargo 5546 (HAS); Capivari do Sul, Águas Belas, fl., Oct 1989, V.F. Nunes & G. Rudh 495 (HAS); Charqueadas, Capão da Roça, fl., Sep 1986, J. Mattos & N. Mattos 30155 (HAS); Flores da Cunha, fl., 30 Oct 1999, L. Scur 102 (HUCS); Galópolis, Arroio Pinhal, fr., 29 Nov 1997, S. Diesel & E. Chavez 1039 (US); Guaíba, Fazenda São Maximiano, fl., 4 Oct 2009, N.I. Matzenbacher 3047 (ICN); Maquiné, Reserva Biológica da Serra Geral, Linha Solidão, trilha da casa do Sr. Lidorino, fl., Nov 2004, R. Schmidt 714 (HAS); Montenegro, Linha Campestre, fl., fr., 14 Nov 1948, A. Sehnem 3527 (PACA); fl., fr., 18 Oct 1950, A. Sehnem 4956 (CORD, FLOR, INPA, HBR, PACA, PEL, SI, UNOP); Polo Petroquímico, fr., Oct 1977, I. Ungaretti 758 (HAS); sub-região C, fl., Nov 1977, T. Buselato 113 (HAS); Osório, Terra de Areia, km 79, fl., Sep 1986, M. Bassan et al. 507 (HAS); Porto Alegre, Campo Novo, fl., fr., 14 Oct 2014, M.O.O. Pellegrini & F. Santos-Silva 449 (RB); Morro das Abertas, fl., fr., 30 Sep 1949, B. Rambo 43678 (HBR, K, PACA); Morro Santana, fl., fr., 5 Oct 1949, B. Rambo 43767 (HBR, PACA, US); São Francisco de Paula, RS-235, fl., 7 Nov 1999, R.A. Wasum 250 (HUCS, L, MBM); Reserva Biológica do Lami, fl., Sep 2003, A.S. Mello & D. Fuhro s.n. (HAS no. 45476); São Leopoldo, arredores de São Leopoldo, fl., Sep 1941, J. Eugênio 439 (NY); Torres, Arroio do Sal, fl., Sep 1985, N. Silveira et al. 3521 (HAS); Estiva, km 48 da estrada para Cidreira, fl., 22 Sep 1972, B. Irgang & L. Baptista 10224 (CORD, CTES, ICN); Itapuã, Granja Neugebauer, fl., fr., 11 Oct 1950, B. Rambo 48926 (HBR, PACA); fl., Oct 1984, N. Silveira et al. 2059 (HAS); fl., 8 Sep 1985, D.B. Falkenberg 3108 (FLOR, RB); Morro da Pedreira, fl., Oct 1979, O. Bueno 1847 (HAS); Vale do Sol, Morro do Es pelho, Spielgerberg, fl., fr., 27 Oct 1992, J.L. Waechter 2529 (ICN, PEL). Santa Catarina: s.loc., fl., fr., s.dat., D. D’Urville s.n. (P barcode P02173875); Abelardo Luz, 4 km N of Abelardo Luz, fl., fr., 23 Oct 1964, L.B. Smith & R. Reitz 12878 (FLOR, HBR, P, R, US); Blumenau, Morro do Sapo, Parque Nacional Serra do Itajaí, fl., fr., 21 Jan 2013, L.A. Funez et al. 1610 (FURB); Bom Retiro, Fazenda Campo dos Padres, fl., fr., 17-19 Nov 1956, L.B. Smith & R. Klein 7726 (HBR, NY, P, R, RB, US); Fazenda Santo Antônio, Campo dos Padres, fl., fr., 23 Jan 1957, L.B. Smith & R. Reitz 10356 (HBR, P, US); Caçador, Pinheiral, fl., fr., 24 Nov 1956, L.B. Smith & R.M. Klein 7912 (HBR, P, R, NY, US); fl., fr., 21 Dec 1956, L.B. Smith & R. Reitz 8964 (HBR, R, US); Campo Novo, acesso alternativo ao Campo dos Padres, fl., fr., 12 Nov 2011, A.L. Gasper et al. 2916 (FURB, HURB); Cerro Negro, margem do Rio Tijolos, fl., fr., 22 Mar 2007, C.R. Grippa 33 (FURB); Grão Pará, Serra do Corvo Branco, fl., 4 Oct 2014, M.O.O. Pellegrini et al. 435 (RB); Itapema, São Paulinho, fl., 23 Sep 2009, A.S. Mello et al. 472 (FLOR); Itapiranga, near Rio Peperi-Guaçu, fl., fr., 17 Oct 1964, L.B. Smith & R. Reitz 12677 (HBR, NY, P, US); Joinville, estrada Dona Francisca, fl., fr., 4 Oct 1957, R. Reitz & R.M. Klein 4997 (HBR, US); Lauro Müller, Serra Rio do Rastro, fl., 14 Jan 1959, R. Reitz & R.M. Klein 8219 (HBR); Nova Trento, Rio Veado, fl., fr., 29 Sep 2010, A. Korte & A. Kniess 4496 (FURB, RB); Presidente Nereu, Braço Thieme, fl., fr., 15 Oct 2009, A. Korte & A. Kniess 433 (FURB, HURB); São Bento do Sul, Rio Natal, linha férrea, próximo ao CEPA Rugendas, fl., fr., 28 Sep 2014, M.O.O. Pellegrini & P. Schwirkowski 424 (RB); fl., fr., 30 Aug 2015, P. Schwirkowski 1204 (FURB); Serra Alta, Ponte do Rio Banhados, fl., P. Schwirkowski 197 (MBM); São Joaquim, fl., Oct 1961, J. Mattos s.n. (HAS no. 67802); Morro da Igreja, Campestre de Malacara, fl., Jan 1960, J. Mattos 7465 (HAS); Timbó, Parque Ecológico Freymund Germer, Morro Azul, fl., fr., 23 Aug 2012, L.A. Funez 775 (FURB, HUCS); fl., fr., 2 Oct 2014, M.O.O. Pellegrini et al. 431 (RB); Urubici, Avencal, Véu da Noiva, fl., fr., 15 Jan 2013, L.A. Funez & A.E. Zermiani 1400 (FURB, HUCS); fl., 5 Oct 2014, M.O.O. Pellegrini et al. 442 (RB); Morro da Igreja, fl., 4 Dec 1992, D.B. Falkenberg & F.A. Silva Filho 5859 (FLOR, RB). PARAGUAY. Alto Paraná: In regione fluminis, fl., 1909-1910, K. Fiebrig 5470 (SI). Guairá: Cordillera de Ybytyruzú, Ladero W del Cerro de Peró, 2 km E del Destacamento Tororo, fl., fr., 12 Nov 1988, E.M. Zardini 8010 (FCQ, K, MO). URUGUAY. Lavalleja: Cerro Arequita, fl., fr., 11 Oct 1970, H.A. Fabris & F.O. Zuloaga 7870 (LP); Penitente, fl., fr., 5 Nov 1933, W.G.H. Herter 1132a (U). Montevideo: s.loc., fl., fr., 1856, A. Courbon s.n. (P barcode P02173871); Bois de Santa Lucia, fl., 1 Nov 1969, M. Fruchard 930 (K, P); fl., fr., 1 Nov 1974, M. Fruchard s.n. (P barcodes P02174018, P02174023); fl., Mar 1976, M. Fruchard s.n. (P barcode P02174019, P02174022); Sierra de Animas, E of Montevideo, fl., 22 Nov 1981, L.R. Landrum, 3857 (US). Río Negro: Yapeyú, Paso Yapeyú, fl., fr., 15 Jun 1914, M.B. Berro 6061 (K). Tacuarembó: s.loc., fl., s.dat., W.G.F. Herter 1132 (BA, SI); Gruta de los Helechos, fl., fr., 28 Sep 1928, W.G.F. Herter 19 (SI).

Distribution and habitat.

Tradescantia tenella is known to occur in Argentina, Brazil (states of Paraná, Santa Catarina and Rio Grande do Sul), Paraguay and Uruguay; in the Atlantic Forest, Chaco and Pampa domains (Fig. 29 ). It can be found growing understorey in shaded and moist forests, between rocks near waterfalls and in clay ravines, as terrestrial, rupicolous or epiphyte.

Phenology.

It was found in bloom and fruit from August to January but peaking during October.

Etymology.

The epithet " tenella " means “delicate”, “small”, probably making reference to its delicate appearance and also to the small portion available to Kunth when describing the species.

Conservation status.

Tradescantia tenella possesses a wide EOO (ca. 791,707.235 km2), and generally forming dense subpopulations. Thus, following the IUCN recommendations ( IUCN 2001), it should be considered Least Concern (LC).

Comments.

Tradescantia tenella is one of the most peculiar species from the T. fluminensis clade. It possesses a definite base, erect and succulent stems (Fig. 28A ) and flowers that range from white to pink (Fig. 28H, I ), which are characters more commonly observed in species belonging to the T. crassula group. Nonetheless, it possesses involute ptyxis, subpetiolate leaves (Fig. 28E ), saccate cincinni bracts (Fig. 28F, H, I ), style as long as the stamens (Fig. 28H, I ), seeds not cleft towards the embryotega and hilum shorter than ½ the length of the seed (Fig. 28J ). These characters undoubtedly place T. tenella and related species (i.e. T. atlantica and T. tucumanensis ) in the T. fluminensis group ( Pellegrini 2017). Due to its peculiar morphology, T. tenella can be confused with species belonging to the T. crassula and T. fluminensis groups. Tradescantia tenella can be confused with T. seubertiana from the T. crassula group, due to their delicate habit, definite base, erect and succulent stems, unequal cincinni bracts and pink flowers. Nonetheless, it can be differentiated by its generally densely branched to fruticose stems (vs. little branched, branching at the base or rarely branching at the upper half in T. seubertiana ), subpetiolate leaves with impressed secondary veins (vs. sessile with inconspicuous secondary veins), blades generally sparsely hirsute to hirsute with ciliolate margins (vs. always glabrous with glabrous margins), saccate cincinni bracts (vs. not saccate), pistil as long as the stamens (vs. longer than the stamens), seeds with testa rugose and not cleft towards the embryotega (vs. costate and cleft) and hilum shorter than ½ the length of the seed (vs. longer than ½ the length of the seed). In the T. fluminensis group, T. tenella can be confused with T. mundula due to their generally reduced stature, subpetiolate leaves and blades generally abaxially vinaceous. However, it can be easily differentiated due to its definite base (vs. indefinite in T. mundula ), erect stems (vs. prostrate), leaf-blades generally sparsely hirsute to hirsute (vs. sparsely strigose to strigose), unequal cincinni bracts (vs. equal), sepals glandular pubescent (vs. velutine), petals ranging from white to pink (vs. always white), seeds with rugose testa (vs. costate) and hilum shorter than ½ the length of the seed (vs. equal to ½ the length of the seed). Tradescantia tenella is unquestionably morphologically closely related to T. atlantica and T. tucumanensis , forming the T. tenella complex. The species in this complex share the definite base, erect stems, chartaceous leaf-blades, flowers that range from white to pink, seeds with rugose testa and hilum always shorter than ½ the length of the seeds ( Pellegrini 2017), being differentiated by stem consistency, the presence of a subpetiole, type and distribution of hairs in the sepals and petal morphology (see identification key).

Figures

Figure 28. Tradescantia tenella Kunth. A habit, showing the definite base and fruticose and erect stems B detail of the stem and leaf-sheath, showing the leaf-opposed line of uniseriate hairs and the setose leaf-sheath margin C detail of the adaxial side of the leaf-blade, showing the hirsute indumentum D adaxial side of the leaf-blade, showing the impressed secondary veins and the vinaceous stripe along the midvein E abaxial side of the leaf-blade, showing the subpetiole and the vinaceous colouration F detail of the inflorescence, showing the saccate and strongly unequal cincinni bracts G flower at post-anthesis showing the glandular-pubescent indumentum and the dorsal keels of the sepals H-I flowers H white petalled flower I light pink petaled flower J dorsal and ventral views of the seed, showing the rugose testa not cleft towards the embryotega and the hilum shorter than 1 / 2 the length of the seed. Photos by M. O. O. Pellegrini.

Figure 29. Distribution of Tradescantia tenella Kunth. Orange- Cerrado; Yellow- Chaco and Pantanal; Olive-green- Pampa; Dark green- Atlantic Forest.