Tradescantia ambigua Mart. ex Schult. & Schult.f. in Roemer & Schultes, Syst. Veg. (ed. 15 bis) 7(2): 1170. 1830.

Pellegrini, Marco O. O., Forzza, Rafaela C. & Sakuragui, Cassia M., 2017, Novelties in Brazilian Tradescantia L. (Commelinaceae), PhytoKeys 80, pp. 1-31 : 11-13

Tradescantia ambigua Mart. ex Schult. & Schult.f. in Roemer & Schultes, Syst. Veg. (ed. 15 bis) 7(2): 1170. 1830. Figs 5 , 8

Tradescantia ambigua Lectotype (designated here). BRAZIL. Bahia: Provincia Bahiensis, fl., fr., s.dat., C.F.P. von Martius 140 (M barcode M0243603!).

Tradescantia ambigua var. glabriuscula C.B.Clarke, Monogr. Phan. 3: 292. 1881. Lectotype (designated here). BRAZIL. Piauhy, shady woods between São Gonçalo do Piauí and Campos, fl., Feb 1819, G. Gardner 2334 (K barcode K000363268!; isolectotype: BM barcode BM001209590!).

Diagnosis.

Herbs perennial, with a definite base, terrestrial to rupicolous. Roots thick, tuberous, brown to dark-brown, densely to sparsely pilose with brown to dark-brown hairs emerging from the rhizome and from the basal-most nodes. Stems erect, succulent, unbranched, rarely branched near the base; internodes green to vinaceous to reddish brown, sometimes with green striations, sparsely velutine, becoming glabrous at age, hairs hyaline. Leaves spirally-alternate, evenly distributed along the stems, sessile, the apical ones gradually smaller than the basal ones; sheaths green, hispid, hairs hyaline, margins hispid, hairs hyaline; lamina crass, flat, light to medium green on both sides, lanceolate to ovate, rarely obovate, adaxially sparsely hispid, becoming glabrous when mature, abaxially densely hispid, hairs hyaline, base truncate to amplexicaulous, margins vinaceous to reddish brown, ciliate, apex acuminate; midvein conspicuous, impressed adaxially, prominently obtuse abaxially, secondary veins inconspicuous to slightly conspicuous on both sides. Inflorescences (main florescences) consisting of a sessile double-cincinni fused back to back, axillary in the uppermost nodes; peduncles inconspicuous; basal bract inconspicuous, tubular, hyaline, glabrous; peduncle bracts absent; supernumerary bracts sometimes present, 1-3 per inflorescence, similar in shape and size to the cincinni bracts; cincinni bracts reduced, light green, hispid, base non-saccate; cincinni 6-12-flowered; bracteoles inconspicuous, imbricate, linear-triangular to triangular, hyaline. Flowers bisexual, actinomorphic, flat (not forming a floral tube); floral buds ovoid, light to medium green, rarely pink; pedicels light to medium green, rarely pink, velutine to hispid, hairs eglandular, hyaline; sepals 3, equal, ovate, cucullate, dorsally not keeled, light to medium green, rarely pink, velutine to hispid, hairs eglandular, hyaline, apex acute, margins hyaline light-green, persistent in fruit; petals 3, equal, sessile, elliptic to ovate to rhomboid, white to pale lilac to lilac to light pink to pink, base cuneate, margins entire, apex acute; stamens 6, equal, filaments light pink to pink to dark pink, rarely white, medially densely bearded with moniliform, light pink to pink to dark pink hairs, straight at anthesis, coiling at post anthesis, connective expanded, rectangular, yellow to orange, anthers sacs curved, yellow, pollen yellow; ovary subglobose, 3-loculate, white, smooth, densely velutine, style straight, white to light pink to pink, stigma capitulate, white to light pink, pistil longer than the stamens. Capsules subglobose, apiculate due to persistent style apex, light green when immature, light brown when mature, velutine, smooth, 3-valved. Seeds uniseriate, 2 per locule, ellipsoid to broadly ellipsoid, not cleft towards the embryotega, ventrally flattened, testa grey to greyish brown, farinose, scrobiculate arranged in ridges radiating from the embryotega; embryotega dorsal, conspicuous, with a prominent apicule; hilum linear, ½ the length of the seed.

Specimens seen.

BRAZIL. Alagoas: Arapiraca, estrada em direção de Jaramataia, ca. 40km da cidade de Arapiraca, fl., 13 Jun 1980, V.C. Lima et al. 77 (IPA); Pão de Açúcar, caminho para Ilha do Ferro, fl., fr., 21 Jun 2002, R.P. Lyra-Lemos 6828 (HUEFS, MAC); Poço das Trincheira, Sítio Saco do Ramalho, fl., fr., 24 Aug 1983, M.N.R. Staviski et al. 643 (MAC, MG). Bahia: Cachoeira, Morro Belo, Vale dos Rios Paraguaçú e Jacuípe, fl., fr., Aug 1980, Grupo Scardino et al. 513 (CEPEC); Caculé, ca. 4.7 km E da sede municipal, estrada que leva à torre de televisão, fl., 30 Mar 2001, J.G. Jardim et al. 3213 (CEPEC, HUEFS, RB); Feira de Santana, distrito de Ipuaçu, fl., fr., 26 Jul 2003, F. França et al. 4798 (HUEFS, HRCB); loc. cit., fl., 19 May 2005, A.P.L. Couto et al. 96 (HUEFS); loc. cit., inselberg Monte Alto, fl., 19 Jun 2006, E. Melo & B.M. Silva 4453 (HUEFS); loc. cit., fl., fr., 8 Jul 2006, C.T. Lima et al. 39 (HUEFS); Itaberaba, Fazenda Morros, fl., fr., 15 Sep 1984, G. Hatschbach 48199 (MBM); Milagres, Morro Pé da Serra, fl., 16 Mar 1997, F. França et al. 2174 (HUEFS, UEC); Paulo Afonso, Raso da Catarina, Mata das Pororocas, fl., 10 Jun 1983, L.P. Queiroz 561 (ALCB, HUEFS, IPA); Riachão do Jacuípe, fl., fr., 6 Jun 2009, E. Melo et al. 6244 (HUEFS). Ceará: Aiuaba, Estação Ecológica de Aiuaba, Gameleira de Cima, fl., 9 Apr 1997, L.W. Lima-Verde et al. 570 (EAC); loc. cit., fl., 9 Apr 1997, L.W. Lima-Verde et al. 573 (EAC); Carnaubal, Planalto do Ibiapaba, fl., 30 Apr 2010, E.M. Marreira et al. 84 (HUEFS, HUVA); Crateús, Sertão de Crateús, Ibiapaba Norte, Picote, fl., fr., 21 May 1997, M.A. Figueiredo s.n. (EAC25685); General Sampaio, RPPN Fancy Nunes, fl., 25 May 2007, M.F. Moro et al. 137 (EAC); Ipueiras, Olho D’água dos Galvão, Nova Fátima, fl., fr., 20 Apr 2014, A.S.F. Castro 2802 (EAC); Itapagé, Serrote do Meio, Pitombeira, fl., 30 Mar 2002, A.S.F. Castro 1182 (EAC); Meruoca, Serra de Meruoca, Sítio Santo Antônio, fl., 15 Feb 1957, A. Fernandes s.n. (EAC1699); loc. cit., fl., 3 Mar 1962, A. Fernandes s.n. (EAC2158); Monsenhor Tabosa, Serra Branca/Serra das Matas, fl., 6 Mar 2000, A.S.F. Castro 804 (EAC); Novo Oriente, Baixa Fria, fl., fr., 4 May 1991, F.S. Araújo 445 (EAC); Pentecoste, Serra do Tamanduá, fl., 31 Mar 2001, A. Andrade s.n. (EAC30590); Santa Quitéria, Serra do Pajé, Fazenda Itan de Cima, fl., fr., 7 May 1997, L.W. Lima-Verde 733 (EAC); loc. cit., fl., fr., 7 May 1997, L.W. Lima-Verde 734 (EAC); loc. cit., Fazenda Itataia, fl., 24 Apr 1984, A. Fernandes et al. s.n. (EAC12489); loc. cit., Subida da Serra, cerca de 2.8km NE da Fazenda Itataia, fl., 27 Apr 2012, J. Paula-Souza et al. 11037 (EAC, ESA, RB); Tianguá, Chapada da Ibiapaba, Cachoeira do Frade, fl., fr., 30 Apr 1987, A. Fernandes & Matos s.n. (EAC15125, IPA69126). Goiás: Lavandeira, 5.5km de Lavandeira em direção a Aurora do Tocantins, fl., 25 Jan 2005, J. Paula-Souza et al. 4654 (ESA, RB). Minas Gerais: s.loc., s.dat., fl., A.F.M. Glaziou 14362 (US); Januária, Brejo do Amparo, Serra do Brejo, fl., 3 Jan 1970, J.P. Carauta 1058 (RB); loc. cit., 15 km na estrada a W de Januária para a Serra das Araras, fl., fr., 20 Apr 1973, W.R. Anderson et al. 9220 (MO, UB); loc. cit., Barreiro, estrada vicinal a partir do trevo do aeroporto, fl., 4 Apr 2016, C.N. Fraga 3654 (RB); Pains, st., 23 Jan 1991, M.A. Rollo s.n. (RB00898260, SPF). Paraíba: Pocinhos, Mubuco, fl., fr., 8 Jul 1994, A.M. Miranda & L.P. Félix 1844 (HST, PEUFR, RB, US); Remígio, Agreste, Escola Agronômica do Nordeste, fl., fr., 8 Aug 1958, J.C. Moraes 1854 (EAN, RB); São José dos Cordeiros, fl., 23 Mar 2003, I.B. Lima et al. 83 (HUEFS). Pernambuco: Alagoinha, Serra do Gavião, fl., fr., 8 Aug 2000, A. Viana et al. 75 (IPA); Arcoverde, Estação Experimental, fl., fr., 22 Jul 1971, Andrade-Lima 71-6399 (IPA); Betania, Serra dos Arrombadores, fl., 6 Apr 2002, S.M.F. Neto et al. 2 (IPA); Buique, Parque Nacional do Catimbau, perto da entrada da trilha do cânion, fl., fr., 16 May 2006, E.A. Rocha et al. 1481 (IPA); loc. cit., Vale do Catimbau, trilha das Torres, fl., fr., 18 Jun 2008, R. Pereira et al. 2760 (HUEFS, IPA); Pesqueira, Serra do Gavião, fl., fl., 19 Jun 2005, M. Oliveira 1811 (IPA); Ouricuri, margem da estrada Lagoa-Ouricuri, fl., 4 May 1971, E.P. Heringer et al. 499 (IPA, PEUFR, R, RB, UB); São Caetano, RPPN Pedra do Cachorro, Subida florestal do afloramento rochoso granítico, fl., fr., 19 Jun 2011, K. Mendes, 700 (ASE). Rio Grande do Norte: Bodó, fl., 4 May 2014, E.O. Moura et al. 161 (UFRN); Florânia, rodovia para Tenente Laurentino ca. 6 km da sede municipal, Serra de Santana, fl., 29 May 2010, J.G. Jardim et al. 5768 (RB, UFRN); Serra de São Bento, fl., L.M. Versieux et al. 548 (HURB, RB, UFRN). Sergipe: Canindé de São Francisco, fl., 1 Sep 2014, G.S. Freire 116 (ASE); Frei Paulo, 6km após o povoado Mocambo, entrada para mata, fl., 26 Jun 1981, M. Fonseca 517 (ASE); loc. cit., fl., fr., 6 Aug 1987, G. Viana 1925 (ASE, HURB); Nossa Senhora da Glória, Fazenda Olhos d’Água, fl., fr., 06 Aug 1982, E. Gomes 114 (ASE); loc. cit., fl., fr., 1 Sep 1983, G. Viana 765 (ASE, HURB); loc. cit., fl., 6 May 1986, G. Viana 1456 (ASE); Porto da Folha, povoado Lagoa do Rancho, fl., fr., 20 Jul 2006, E. Córdula et al. 115 (HUEFS, UFP); loc. cit., Fazenda São Pedro, fl., 19 Apr 2011, D.G. Oliveira 150 (ASE, MAC); loc. cit., fl., fr., 6 Aug 2012, A.P. Prata at al. 3212 (ASE); loc. cit, fl., fr., 5 Aug 2014, L.A.S. Santos 1158 (ASE, RB). Without state: s.loc., fl., M.A. Glaziou 14362 (P, US).

Distribution and habitat.

Tradescantia ambigua is endemic to Northeastern Brazil (states of Alagoas, Bahia, Ceará, Paraíba, Pernambuco, Piauí, Rio Grande do Norte, and Sergipe), also reaching the states of Goiás and Minas Gerais. It grows in moist and shady areas, between shrubs and patchy forests in the Caatinga and Cerrado domains (Fig. 8 ).

Phenology.

It was found in bloom and fruit from January to August.

Conservation status.

Tradescantia ambigua possesses a wide EOO (ca. 1,057,693.924 km2), and following the IUCN recommendations ( IUCN 2001), it should be considered Least Concern (LC). However, when taking the AOO into consideration, it is considerably reduced (ca. 216.000 km2). Furthermore, The Caatinga and Cerrado domains are greatly threatened by human activities such as deforestation, cattle breeding, and various crops. Thus, following the IUCN (2001) recommendations, T. ambigua should be considered Endangered [EN, A2c+B2ab(ii, iii, iv, v)+C2a(i)].

Nomenclatural notes.

When describing T. ambigua , Schultes and Schultes (1830) mention that their new species is based on a Martius specimen from the Province of Bahia, but with no reference to herbaria or collector number. While consulting M we came across a specimen (Martius 140) matching perfectly the protologue, and annotated in Martius’s handwriting. Thus, it is here designated as the lectotype.

When describing T. ambigua var. glabriuscula , Clarke (1881) only lists the collection Gardner 2334. However, Clarke makes no reference to the herbaria in which this specimen might be distributed. After analyzing several collections, we found specimens of Gardner 2334 at BM and K. According to Stafleu and Cowan (1976), Clarke had access to both collections, and many of the type specimens for names described by him were commonly from either of the two herbaria. The specimen at K is composed of a much longer stem, containing a greater number of leaves, inflorescences and flowers. Added to that, it is annotated on Clarke’s handwriting, making it the obvious choice for a lectotype.

Morphological notes.

Tradescantia ambigua , as most species in T. sect. Mandonia , presents a high degree of morphological variation. The plants vary greatly in size, branching of the stem, shape of the leaves, pubescence of the leaves, pubescence of the pedicels and sepals, and shape and color of the petals. Nonetheless, this variation has no obvious geographical pattern and seems rather random across its distribution range. Thus, don’t recognize any infraspecific taxa for T. ambigua .

Figures

Figure 5. Tradescantia ambigua Mart. A sterile habit, showing the amplexicaulous leaf-blades B detail of the stem and leaf-sheath, showing the densely hispid leaf-sheath and blade C detail of the leaf-blade, showing the reddish, ciliate margin, and the sparsely hispid blade D fertile habit, showing the axillary, sessile inflorescences E removed leaf, exposing the sessile inflorescence and showing the reduced cincinni bracts (arrows) F post-anthesis flower, showing the apically spirally-coiled filaments. Photograph A by E. O. Moura, D & F by L. J. Leitao, B-C & E by M. O. O. Pellegrini.

Figure 8. Distribution map of studied Tradescantia L. in the South American domains. Full squares - T. crassula; White squares - T. chrysophylla; Triangles - T. valida; Circles - T. ambigua; Stars - T. boliviana. Light green- Amazon Forest; Orange- Cerrado; Red- Caatinga; Yellow- Chaco and Pantanal; Olive-green- Pampa; Dark green- Atlantic Forest; Purple- Andean Yungas.