Thinouia ternata Radlk.

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

10. Thinouia ternata Radlk. , Sitzungsber. Math. - Phys. Cl. Königl. Bayer. Akad. Wiss. München 8: 282. 1878

Figs 19 D , 20 , 21

Banisteria ternata Vell. , Fl. Fluminensis: 159. 1829 (“ 1825 ”) (nom. illeg.).

Type.

Brazil. Minas Gerais • Lagoa Santa , s. d. Warming s. n .. (lectotype, designated here: P [ P 06695484 ] [image!] – epitype, designated here: Brazil. Bahia. Rui Barbosa. ARIE Serra do Orobó, Fazenda Bom Jardim [12°19'43"S, 40°28'34"W] 591 m, 21 Apr 2006, D. Cardoso and K. S. Matos 1245 RB! [ RB 01464762 ]; isoepitype: NY!, HUEFS [ HUEFS 108414 ] [image!]) .

Description.

Tendrilled liana; stem pubescent or tomentose and glabrescent when mature, lenticels round or elliptic; cross-section simple. Leaves trifoliolate; stipules ca. 0.5 mm long, tomentose, triangular; petiole 3.5–7.7 cm long, terete or semiterete and keeled along the middle, striate, pubescent to tomentose; terminal petiolule 0.3–0.7 cm long, semiterete; lateral petiolules 0.2–0.5 cm long; leaflets with adaxial side tomentose to glabrescent, sometimes strigose, the abaxial side tomentose; leaflet secondary venation craspedodromous; secondary veins 4–6 pairs, alternate or subalternate, spacing irregular, with domatia on the abaxial side of secondary veins axils; intersecondaries present; tertiary veins mixed opposite-alternate percurrent or alternate percurrent; margins dentate or serrate, with (7) 8–12 vestigial teeth on each side, reduced to inconspicuous glands; terminal leaflet 5.3–10.6 × 4.4–5.6 cm, broadly elliptic, obtrullate or ovate, the apex acuminate and mucronate, the base decurrent; lateral leaflet 4.2–8.9 × 2.3–3.8 cm, ovate, asymmetrical, the apex acute to acuminate, mucronate, the base truncate to rounded. Thyrses axillary or terminal, umbelliform, 1.5–5.3 cm long; peduncle 0.5–4.2 cm long; secondary peduncle 0.1–0.5 cm long; cincinni numerous, peduncle of cincinnus 2–3 mm long, tomentose. Flower 5–5.2 mm long, pedicel 2–3 mm long, pilose or sparsely pilose; sepals ca. 0.5 mm long, triangular, abaxially pilose or sparsely pubescent, adaxially glabrous or sometimes villous, ciliate; petals 1–1.7 mm long, oblanceolate, spatulate, clawed, erose, adaxially villous and abaxially glabrous; petal appendages <0.5 mm long, shorter than the petal, bifid, villous; nectary disc annular, glabrous. Staminate flowers with stamens 8, ca. 2.5 mm long, the filaments villous on lower half, the anthers ca. 0.5 mm long, glabrous, papillose; pistillode ca. 0.4 mm long, villous. Pistillate flower with staminodes 8, ca. 1 mm long, the filaments villous ca. on lower half, the anthers ca. 0.3 mm, glabrous, papillose; pistil ca. 4 mm long, glabrous at base, villous from middle to apex. Fruits chartaceous, 3–4 × 2.5 cm; accrescent pedicel 4.7–5.2 cm long; stipe 6.2–7 mm long; seed locule lenticular; epicarp glabrous; cavity of seed locule glabrous or with sparse simple or capitate trichomes with uniseriate stalk and unicellular terminal cells. Seed ellipsoid 5.7–7 × 3.6–4.7 cm, glabrous.

Distribution and habitat.

This species is endemic to tropical and subtropical Brazil, found in moist broadleaf forests in ombrophilous, semi-deciduous and deciduous forests, and along streams, on limestone outcrops, and forest margins, in Bahia, Espírito Santo, Minas Gerais and Rio de Janeiro states (Fig. 18 D ), at 215–950 m elevation. Flowering from February to April, and fruiting from May to October.

Notes.

Thinouia ternata is sister to T. mucronata and T. paraguayensis (see comments under T. paraguayensis ) (Fig. 4 ). They are morphologically similar, with simple stems, leaflets with mucronate apex, flowers 3–5 mm long, and fruits chartaceous. Thinouia ternata can be distinguished from T. mucronata by the lateral leaflet that are truncate to rounded at the base (vs. decurrent) and by the craspedodromous (vs. semi-craspedodromous) venation.

Banisteria ternata Vell. is the older name for this species. However, as it is a later homonym of Banisteria ternata DC. , therefore the name is illegitimate. Consequently, the name Thinouia ternata should be credited to Radlkofer (1878), not a combination based on Vellozo’s name. In the protologue of T. ternata Radlk. , Radlkofer cited a collection of Warming from Minas Gerais in addition to the name of Vellozo. We designate the collection of Warming deposited at P as the lectotype, as a specimen is preferable over an illustration. Additionally, we designated an epitype because the lectotype does not have the necessary features in order to fix this name with certainty to a given species.

Conservation status.

Thinouia ternata is represented by a few records from four states of Brazil’s Atlantic Forest, with an EOO of 264,322.39 km 2 and an AOO of 28.00 km 2 in the anthropically modified semi-deciduous forests. Thus, it should be regarded as Vulnerable [ VU, B 2 ab (ii, iii, iv)], due to its range of distribution being less than 100 km 2 and the number of locations being ≤ 10. Additionally, these species have continuously declining habitat quality, principally in the restinga vegetation where it faces intense pressure from human occupation.

Selected specimens examined.

Brazil. Bahia • Mun. Itabuna, Margem do Rio Pardo , 23 May 1968, Belém 3597 ( CEPEC, F, IAN, NY) • Mun. Itajú do Colônia, ca. 81 km de Santa Cruz da Vitória , 25 Feb 2021, Medeiros and Toledo 4489 ( CEPEC, RB, SPF, UFACPZ, US) . Espírito Santo • Mun. Muniz Freire, Vieira Machado , 17 Feb 1993, Souza 439 ( CVRD) . Minas Gerais • Serra do Espinhaço, ca. 5 km NE of Francisco de Sá , 13 Feb 1969, Irwin et al. 23219 ( NY, UB) • Mun. Janaúba, Ribeirão Poções , 13 Feb 1991, Hatschbach 55100 ( MBM) • Mun. Pains , 613 m, 12 Jul 2006, Borges et al. 224 ( RB, RBR) • Fazenda Amargoso , 750–810 m, 25 May 2003, Melo et al. 625 ( BHCB, RB) . Rio de Janeiro • Mun. Nova Friburgo, caminho para a Pedra do Cão Sentado , 27 Oct 1986, Somner et al. 544 ( RBR) .

Figures

Figure 4. Maximum clade credibility tree from a Bayesian analysis of the combined two-marker dataset for Thinouia and outgroups. Bayesian posterior probability values are indicated above the branches.

Figure 18. Thinouia silveirae H. Medeiros A portion of flowering branch B leaf C indumentum on leaflets D staminate flower with portion of perianth removed showing nectary disc E pistillate flower F petal with bifid and marginal appendage, dorsal [abaxial] view G petal with bifid appendage, frontal [adaxial] view H stamen of staminate flower I fruit J mericarp K indumentum of epicarp L indumentum detail of locule cavity M capitate trichomes with uniseriate stalk and multicellular terminal cells from locule cavity N simples trichomes on locule cavity O seed P embryo (A – H from Medeiros 4496 I – P from Medeiros 2191). Illustration by Maria Alice de Rezende.

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.

Figure 20. Thinouia ternata Radlk. A fertile branch B leaf C stem with lenticellate bark D portion of young synflorescences E mature fruit F stem cross-section, simple G partial view of leaflets showing secondary veins and serrulate margins [Medeiros 4489 (A, B, D, G); Daneu 746 (C, E – F); photos: A, B, D, G by H. Medeiros C, E, F by L. Daneu].

Figure 21. Thinouia ternata Radlk. A flowering branch B leaf C staminate flower D petal with bifid appendage, dorsal [abaxial] view E stamen of staminate flower F infructescence G indumentum detail of locule cavity H capitate trichomes with uniseriate stalk and unicellular terminal cells from locule cavity I pistillate flower with portion of perianth removed showing the gynoecium and nectary disc J seed K embryo (A – E from Amorim 3580 H – M from Cardoso 1245). Illustration by Maria Alice de Rezende.