Thinouia scandens (Cambess.) Triana & Planch.

Medeiros, Herison, Acevedo-Rodríguez, Pedro, de Carvalho Lopes, Jenifer & Forzza, Rafaela Campostrini, 2025, Taxonomic revision and phylogenetic relationships of Thinouia (Sapindaceae), a neotropical genus, PhytoKeys 252, pp. 207-273 : 207-273

8. Thinouia scandens (Cambess.) Triana & Planch. , Ann. Sci. Bot. Ser. 4, 18: 369. 1862

Figs 16 , 19 B

Thouinia scandens Cambess. in A. de Saint-Hilaire, Flora Brasiliae Meridionalis 1: 384. 1828. Thinouia scandens forma genuina nom. invalid.

Paullinia caudata Vell. , Fl. Fluminensis 159. 1829 (“ 1825 ”); Fl. Fluminensis Icones 4: tab. 31. 1831 (“ 1827 ”). Thinouia scandens forma caudata (Vell.) Radlk. , Sitzungsber. Math. - Phys. Cl. Königl. Bayer. Akad. Wiss. München. 8 (3): 282. 1878. (lectotype, designated here: Brasil. [Rio de Janeiro or São Paulo] no locality or habitat given; [illustration] Original parchment plate Flora Fluminensis in the Manuscript Section of the Biblioteca Nacional do Rio de Janeiro [cat. no.: mss 1198653 _ 029] and later published in Vellozo, Fl. Fluminensis Icones 4: tab. 31. 1831. [image!]).

Thinouia scandens forma racemosa Radlk. , Sitzungsber. Math. - Phys. Cl. Königl. Bayer. Akad. Wiss. München. 8 (3): 282. 1878. Thouinia macroptera Casar. , Nov. Stirp. Bras. 5: 45. 1843. Carpidiopterix macroptera (Casar.) H. Karst. , Fl. Columb. 2: 45. 1863. Type: Brazil. “ Habitat circa Rio de Janeiro, s. d. [before 1840], Riedel s. n [Casaretto Herb. no. 2479] (lectotype, designated here: TO [image!]).

Thinouia scandens forma areolata Radlk. nom. nud.

Type.

Brasil. Rio de Janeiro • “ Nascitur in sylvis primaevis provinciae Rio de Janeiro, “ Florebat Februario ”, Saint-Hilaire s. n .. (lectotype, here designated: MPU [ MPU 010891 ] [image!]) .

Description.

Tendrilled liana; stem cylindrical or 4–5 lobed, glabrous, pubescent or tomentose, lenticels rounded, elliptic or oblong; cross-section simple or with neo formations when mature. Leaves trifoliolate; stipules ca. 0.5 mm long, tomentose, triangular; petiole 5.6–9.1 cm long, semiterete to canaliculate with keel in the middle, striate, glabrous to pubescent; terminal petiolule 0.8–3.7 cm long, canaliculate with keel in the middle, striate; lateral petiolules with keel in the middle 0.4–1.4 cm long; leaflets with the adaxial side glabrous and the abaxial side glabrous, glabrescent, puberulous or tomentose; the leaflet secondary venation craspedodromous to semicraspedodromous, secondary veins 5–7 pairs, alternate or subalternate, spacing irregular, domatia on abaxial surface of secondary vein axils commonly on lowermost pair of secondary veins; intersecondaries present; tertiary veins alternate percurrent or mixed opposite-alternate percurrent; margins entire, dentate or serrate with 3–9 teeth, reduced to inconspicuous glands; terminal leaflet 5.2–11.7 × 3.1–7 cm, obovate, oblong, oblong-ovate or ovate to very widely ovate, symmetrical or asymmetrical, apex rounded, obtuse, acute or acuminate, mucronate or sometimes emarginate, base rounded to obtuse; lateral leaflets 4.3–12.7 × 2.7–8.1 cm, ovate, oblong, elliptic or lanceolate, asymmetrical, the apex rounded, obtuse, acute or acuminate, mucronate, base truncate or obtuse to rounded. Thyrses axillary or terminal, umbelliform, 2–4 cm long, peduncle 1.5–2 cm long, secondary peduncle 0.2. – 0.5 cm long; cincinni numerous, peduncle of cincinnus 0.6–0.7 cm long, tomentose. Flower 4.5–6 mm long; pedicel 2–3 mm long, pilose or sparsely pubescent; sepals ca. 0.5 mm long, oblong-ovate, abaxially pilose or sparsely pubescent, adaxially glabrous or sometimes villous, ciliate; petals 1.6–2.5 mm long, oblong-spatulate, clawed, erose, adaxially glandular, abaxially glabrous; appendages 0.7–1.5 mm long, shorter than the petals, villous; nectary disc annular, glabrous. Staminate flowers with stamens 8, 2.8–3 mm long, the filaments villous on lower half, the anthers 0.5–0.6 mm long, glabrous, papillose; pistillode ca. 0.5 mm villous. Pistillate flower with staminodes 8, 1.5–1.7 mm long, villous throughout; pistil ca. 4.5 mm long, the ovary adpressed-pubescent along dorsal edges, the stigma and style tomentose. Fruits chartaceous, 4.3–7.5 × 2.5–4.1 cm; accrescent pedicel 2.3–6.1 cm long; stipe 4.3–9.7 cm long; seed locule subglobose to lenticular; epicarp glabrous; cavity of seed locule pubescent with capitate trichomes; capitate trichomes with uniseriate stalk and multicellular terminal cells. Seed ellipsoid, 6–7.4 × 4.3–5.6 cm, glabrous.

Distribution and habitat.

Thinouia scandens is endemic to tropical and subtropical moist broadleaf forests in SE Brazil, between 40–1200 m, in gallery forests, semi-deciduous forests, tabuleiro forests and ombrophilous forests in Bahia, Espírito Santo, Minas Gerais, São Paulo and Rio de Janeiro states (Fig. 19 B ). Flowering from December to April and fruiting from January to October.

Notes.

Thinouia scandens is easily recognized by the leaflets with entire, dentate or serrate margins, with 3–9 pairs teeth per side or with teeth reduced to inconspicuous glands; venation craspedodromous to semicraspedodromous; fruits 4.3–7.5 cm long; and locule cavity densely pubescent with capitate trichomes. Radlkofer (1878, 1931–1934) recognized several taxonomic forms within T. scandens based on variations of leaf size, form and pubescence. However, our study found that these characters overlap. Additionally, in our molecular phylogenetic studies the samples representing T. scandens were recovered with very strong support in a clade. Therefore, we considered the forms proposed by Radlkofer as synonyms of T. scandens .

In the protologue of the Thinouia scandens (Cambess.) Triana & Planch. only the place of collection was indicated without mentioning a particular specimen. We have found three specimens that correspond to the collector and identified by the basionym species author: MPU 010891, P 00754921, and P 00754922. Of these, only in the former does the locality correspond with that of the protologue and therefore has been chosen as the lectotype. For the name Paullinia caudata Vell. , we have selected as the lectotype the illustration of Vellozo (1831, t. 31), which is the only original material available for this name, Paullinia caudata . This illustration clearly fits in the Thinouia scandens due its elliptic to ovate leaves with margins entire to dentate-serrate and the long fruits. Thinouia scandens f. racemosa was based upon two elements, i. e., the illegitimate Paullinia racemosa of Vellozo (1831, t. 29) and a collection of Riedel s. n. (the type of Thouinia macroptera Casar. ). We have selected the latter as the lectotype, as it is preferable to an illustration.

Conservation status

. Thinouia scandens possesses a broad EOO of 180,117.85 km 2 and an AOO of 136.00 km 2, with many known locations. However, the ombrophilous forest vegetation in SE Brazil, where the species is found, is subject to continuing decline in area and quality of habitat due to anthropic pressure. Despite this, there are no data on population decline to apply other criteria and several conservation units in Brazil protect the species. Thus, it should be regarded as Least Concern (LC).

Selected specimens examined.

Brazil. Bahia • Mun. Almadina, Serra do Corcovado , 20 Mar 2006, Paixão et al. 909 ( CEPEC, RBR) • Mun. Nova Viçosa, Estrada para Nova Viçosa , 22 Feb 2021, Medeiros and Toledo 4486 ( RB, SPF, UFACPZ) • Mun. Porto Seguro, Estação Veracel , 12 Oct 2006, Colman et al. 21 ( ALCB) • Mun. Una, Reserva Biológica do Mico-Leão , 10 Mar 1993, San’t Ana et al. 291 ( CEPEC, SP) . Espírito Santo • Mun. Alegre, São João do Norte , 17 Mar 2009, Couto et al. 1131 ( MBML, VIES) • Mun. Linhares, Estrada paralela ao Rio Doce , 18 Feb 2021, Medeiros and Toledo 4472 ( RB, SPF, UFAPCPZ) • Mun. Nova Venécia, Área de Proteção Ambiental Pedra do Elefante , 329 m, Fraga et al. 2083 ( CEPEC, CTES, MBML, RB, UPCB) • Mun. Regência, Reserva Biológica de Comboios , 24 Jan 1990, Folli 1076 ( US) • Mun. São Mateus, Próximo de Boa Esperança , s. d, Maguanini and Mattos s. n .. ( RB 87950 ) . Minas Gerais • Mun. Alto Caparaó, Parque Nacional do Caparaó , 23 Apr 1998, Leoni 3950 ( RB) • Mun. Carangola, PCH-Carangola , Feb 2007, Leoni et al. 63 ( RB, UFACPZ) • Mun. Faria Lemos, Fazenda Santa Rita , 14 May 2006, Silva 122 ( RB) • Mun. Francisco Sá, ca. 5 km NE of Francisco de São , 950 m, Irwin et al. 23129 ( MG) • Mun. Ipaba , s. d., Pujals s. n .. ( MBM 420905 ) . Rio de Janeiro • Mun. Guapimirim, Parque Nacional da Serra do Órgãos , 734 m, 14 Feb 2021, Medeiros and Toledo 4452 ( NY, RB, SPF, UFACPZ, US) • Mun. Itaperuna, Estrada para São Lourenço , 7 Jun 2004, Marquete et al. 3501 ( IBGE, HRB) • Mun. Mangaratiba. Trilha para o Mirante , 17 Aug 2017, Somner and Acevedo-Rodríguez 1851 ( RBR) • Mun. Natividade, Mata de São Vicente, Morro da Torre , 11 Jun 2006, Gonçalves et al. s. n .. ( RB 00594985 ) • Mun. Niterói, Morro do Cavalhão , 28 Aug 1888, Glaziou et al. 17499 ( P) • Mun. Nova Friburgo, Macaé de Cima , 9 Oct 1993, Vieira and Gurken 429 ( ESA, MBM, NY, RB) • Mun. Paraty, Estrada para o morro do Corisquinho , 10 Mar 1994, Campos 14 ( CTES, RB, RBR) • Mun. Petrópolis, Estrada velha Rio Petrópolis , 1 Sep 1990, Somner et al. 585 ( RBR) • Mun. Piraí, Distrito de Cacaria , 27 May 2009, Somner et al. 1339 ( RBR) • Mun. Rio Bonito, Distrito de Brasília, Fazenda Cachoeira , 13 Aug 1986, Acevedo-Rodríguez et al. 1436 ( MO, NY, RB) • Mun. Rio de Janeiro, Horto Florestal , 28 Apr 1924, Florestal s. n .. ( RB 148992 , S) • Mun. Teresópolis, Parque Nacional da Serra dos Órgãos , 14 Feb 2021, Medeiros and Toledo 4450 ( NY, RB, SPF, UFACPZ, US) . São Paulo • Equipe Morro das Pedras , 1917, Brade 7923 ( R) • Mun. São Paulo. Nativa do Jardim Botânico , 25 Feb 1942, Hoehne s. n .. ( SP 46367 ) .

Figures

Figure 16. Morphological variation in Thinouia scandens (Cambess.) Triana & Planch. A stem cross-section cylindrical, simple B stem cross-section obtusely pentagonal, showing early neo formation C stem cross-section ribbed (lobed), showing neo formations at different stages of development D – F leaf morphological variation G – I fruit morphological variation [Medeiros 4450 (E, H) 4451 (B) 4473 (A, D, G) 4481 (C) 4486 (F) 4488 (I); photos: by H. Medeiros].

Figure 19. Distribution maps of Thinouia species A Thinouia paraguayensis and T. restingae B T. scandens and T. silveirae C T. tomocarpa and T. trifoliolata D T. ternata and T. ventricosa.