Thinouia myriantha 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

4. Thinouia myriantha Triana & Planch. , Ann. Sci. Bot. Ser. 4, 18: 369. 1862

Figs 9 , 10 , 13 C

Carpidiopterix macroptera sensu H. Karst. , Fl. Columb. 2: 45. 1863, not Thouinia macroptera Casar.

Type.

Colombia. Prov. de Bogotá • Tocaima, Limba , alt. 450 m, May 1857, J. Triana s. n .. (lectotype, designated here: MPU [2 sheets] [ MPU 010893 , MPU 010892 ] [image!]) .

Description.

Tendrilled liana 10–15 m; stem cylindrical, 10–12 cm diam., puberulous and ferruginous, lenticels rounded or elliptic and ferruginous; cross-section simple. Leaves trifoliolate; stipules minute, ca. 0.4 mm long, tomentose; petiole 1.8–6 cm long, terete, striate, pubescent, puberulous to glabrescent; terminal petiolule 1–4 cm long, lateral petiolules 0.3–1.5 cm long; leaflets glabrous on both sides, sometimes with sparse trichomes along veins; the leaflet secondary venation eucamptodromous or mixed semicraspedodromous at the apex; secondary veins (4) 5–6 pairs, subalternate or alternate, spacing irregular, with domatia on abaxial side of axils; intersecondaries present; tertiary veins irregular reticulate to mixed alternate-opposite percurrent; margins entire to repand-serrate (rarely serrate), with (2) 4–8 teeth per side, reduced to inconspicuous glands; terminal leaflet 6.5–17.5 (22) × 3.5–10.5 (11.3) cm, elliptic-ovate, apex acute or obtuse, long-apiculate, base truncate, obtuse or rounded; lateral leaflets 5.5–15.5 (17) × 2–8.9 (9.5) cm, ovate, asymmetrical, apex obtuse or acute and acuminate without drip tip, base truncate or rounded, sometimes cordate. Thyrses axillary or terminal, umbelliform, 1.5–10 cm long, peduncle 1–8.6 cm long, secondary peduncle 0.1–1.8 cm long; cincinni numerous, peduncle of cincinni 0.4–0.5 cm long, tomentose. Flower 1–2.5 mm long, pedicel 0.8–3 mm long, pubescent or tomentose; sepals 0.5–1 mm long, oblong-ovate, abaxially villous or slightly villous and adaxially glabrous; petals 0.4–0.8 mm long, lanceolate to obdeltoid, not clawed, villous; petal appendages 0.7–1.5 mm long, longer than the petals, bifid, villous; nectary disc annular, glabrous. Staminate flowers with stamens 8, 2–3 mm long, filaments villous on lower half, anthers glabrous to sparsely villous; pistillode ca. 0.5 mm long, villous. Pistillate flower with staminodes 8, ca. 1.5 mm long, with same indumentum as stamens; pistil ca. 4.5 mm long, ovary tomentose, stigma and styles tomentose. Fruits chartaceous, 2–5.4 × 1–3.2 cm; accrescent pedicel 1.6–3.5 mm long; stipe 2–5.1 mm long; seed locule slightly flattened; epicarp sparsely pubescent; cavity of seed locule with simple unicellular, multicellular and ferruginous trichomes. Seed 6–7.2 × 3.2 mm, ellipsoid, flat.

Distribution and habitat.

Thinouia myriantha is a species widely distributed from Costa Rica to South America, skirting the Amazon basin (i. e., peri-Amazonian distribution sensu de Granville 1992), known from tropical and subtropical moist broadleaf forests in Costa Rica, Panama, Colombia, Venezuela, the Guianas, Ecuador, Peru, Bolivia, and Brazil (Fig. 13 C ). Flowering from November to February, and fruiting from December to August.

Notes.

According to our phylogenetic analyses, Thinouia myriantha is sister to T. silveirae (see comments in T. silveirae ), with both species forming a clade that is sister to T. tomocarpa . These species together form a clade characterized by the (1) petal appendages that are longer than the petal; (2) fruit cocci that are slightly flattened; (3) cross-section of stem simple; and (4) size and shape of leaflets. The species in this clade, however, are differentiated by the distribution of hairs on the stamens. Thinouia myriantha is distinguished by the filaments that are villous only on lower half, white in T. tomocarpa , and the stamens that are villous from the base to the connective (see comments in T. tomocarpa ). Thinouia myriantha , as currently recognized, has an ample distribution with substantial morphological variation, and possibly includes more than one species. The resolution of this issue requires the analysis of additional data, including more molecular, morphometry and anatomical data to fully understand if there is some congruence between phylogenetic results and morphological variation.

In the current study, it was found that only a single collection has been made in the type locality region and that only the specimen housed in MPU was located, so that the MPU specimen is designated here as the lectotype.

Conservation status.

Thinouia myriantha possesses a broad EOO of 5,040,364.60 km 2 and AOO of 168.00 km 2, with more than 10 threat situations and records in conservation units. The EOO values and the number of threat situations extrapolate the threshold for the inclusion of the species in a threat category. Furthermore, several conservation units protect the species. Thus, T. myriantha was considered as Least Concern (LC).

Selected specimens examined.

Bolivia. La Paz • Prov. Abel Iturralde, Parque Nacional Madidi , 535 m, 19 May 2001, Macía et al. 4542 ( US) • Prov. Sud Yungas, Sapecho ca. 5 m E del Río Beni , 28 Mar 1986, Beck 13309 ( US) . Brazil. Acre • Mun. Bujari, Rio Antimary , 12 Dec 2016, Frazão et al. 417 ( SPF, UFACPZ) • Mun. Marechal Thaumaturgo, Rio Bagé , 5 Dec 2000, Daly et al. 10444 ( NY, UFACPZ, US) • Mun. Rio Branco, Área de Proteção Ambiental Lago do Amapá , 20 Nov 2017, Medeiros et al. 3788 ( RB, SPF, UFACPZ) • Mun. Sena Madureira, Reserva Extrativista do Cazumbá-Iracema , 4 Dec 2019, Medeiros et al. 4300 ( NY, RB, SPF, UFACPZ, US) • Mun. Mâncio Lima, Parque Nacional da Serra do Divisor , 8 Dec 2022, Medeiros et al. 4898 ( NY, RB, SPF, UFACPZ, UPCB) . Amazonas • Mun. São Paulo de Olivença, Camatian , 23 Jan 1949, Fróes 23958 ( IAN, UB) . Pará • Mun. Belterra, Flona do Tapajós , 7 Feb 2017, Torke et al. 2024 ( HSTM, RB, UFAPZ) • Mun. Parauapebas, Serra dos Carajás , 10 Jan 1995, Rodrigues 1632 ( IAN) • Mun. Santarém, Floresta Nacional do Tapajós , 29 Apr 2010, Nascimento 33 ( IAN) • Mun. Vitória do Xingu , 3°18'S, 51°47'W, 7 Jan 2015, Gonçalves PSACF _ EX 04702 ( RB, UFACPZ) . Rondônia • Mun. Porto Velho, Parque Nacional do Mapinguari , 13 Dec 2013, Silveira et al. 500 ( INPA, RB, RON) . Colombia. Atlántico • Cerca a Usiacurí , 2 Jan 1949, Molina et al. 19 At 075 ( COL, US) • Barranquilla and vicinity , Dec 1934, Elias 1266 (F- 2, MEDEL, US) . Bolivar • Loma de los Colorados near San Juan de Nepomuceno , 31 Dec 1992, Gentry et al. 78457 ( U, US) • Cartagena. Cerro de la Popa , 4 Feb 1962, Saraiva and Johnson 42 ( COL) . Magdalena • Delta of Magdalena river , 28 May 1935, Dugand 872 ( F) • Roadside 10 km north of Codazzi , 23 Nov 1943, Haught 3867 ( COL, RB, US) • Along stream near La Paz , 12 Jan 1944, Haught 3962 ( COL, MO, US) • Barro Blanco , 29 Nov 1945, Haught 4746 ( COL, F, MEDEL, NY, US) • Santa Marta. Agua Dulce Road , 2 Jan 1898, Smith 882 ( F, MO, NY, U, US) . Meta • Sierra de La Macarena, Río Guapaya , 21 Jan 1950, Philipson et al. 2197 ( COL, MEDEL, US) . Costa Rica. Puntarenas • Parque Nacional Corcovado Sirena Trail , 6 Jan 1989, Kernan 867 ( F, MEXU, MO, US) . San José • Carara National Park , 3 Apr 1993, Gentry et al. 79370 ( MO) . Ecuador. Napo • Tiputini Biodiversity Station , 18 Mar 1998, Burnham et al. 1671 ( F, QCNE, US) • La Joya de los Sachas. Comunidad Indillama , 250 m, 14–28 Jan 1994, Grijalva et al. 450 ( QCNE, MO, US) • Orellana. Via a los Pozos Gacela , 250 m, 8 Aug 1993, Palacios 11034 ( QCNE, US) . French Guiana • Haut Camopi Bauin Oyapock , 1 Feb 1949, De La Rue s. n .. P 0669512 ( P) • Aratai River , 1–2 km downstream, 22 Feb 2003, Acevedo-Rodríguez et al. 12359 ( NY, US) . Guatemala • Izabal bet Virginia and Lago Izabal , 50–100 m, 4 Apr 1940, Steyermark 38774 ( F) . Guyana. [Without Region] • Kanuku Mts., Rapununi R., Crabwood Cr. , 100 m, 3 Jul 1995, Jansen-Jacobs et al. 4314 ( F, MO, P, U, US) . U. Takutu-U. Essequibo • Trewa River 0–5 km N of confluence of Rewa and Kwitaro Rivers , 90 m, 26 Feb 1997, Clarke 3964 ( U, US) . Panama. Panamá • Barro Colorado Is., Zetek , 26 Feb 1971, Foster 2204 ( F) • Serrania de Majé , 300 m, 28 Jan 1984, Churchill and Nevers 4441 ( MO) . Peru. Cuzco • Prov. Cuzco, Campamento San Martín-C , 467 m, 15 Jan 1997, Acevedo-Rodríguez et al. 8788 ( USM) • Prov. La Convención, Distrito Echarate, Chahuares , 805 m, Huamantupa and Carrión 9075 ( MO) . Loreto • Prov. Manu, Puerto Maldonado, Los Amigos Biological Station , 24 Nov 2003, Maceda et al. 1097 ( US) • Prov. Maynas, Iquitos, Estación Experimental del Instituto de Investigaciones de la Amazonía Peruana , 24 Aug 1990, Vásquez et al. 14290 ( MO, US) • Prov. Requena, Jenaro Herrera , 26 Feb 2010, Zárate 14005 ( USM) . Madre de Dios • Cocha Cashu Station , 350 m, 26 Nov 1980, Foster 5905 ( F, NY) • Tambopata Tourist Camp , 260 m, Gentry and Ortiz 78338 ( MO) • Trail from CICRA to Cocha Lobos , 9 Aug 2003, Acevedo-Rodríguez et al. 14262 ( NY, US) . San Martín • Fundo Pampahermosa ( Huicte ), 10 Jun 1964, Schunke-Vigo 6533 ( F, USM) . Ucayali • Upper Ucayali, Mashea , s. d., Tessmann 3314 ( NY) . Suriname. Brokopondo • Brownsberg, Mazaronitop , 23 Nov 2003, van Andel et al. 4485 ( U, US) . Sipaliwini • Sipaliwini Region, Voltzberg Nature Reserve , 100 m, Hoffman et al. 5308 ( US) • Wilhelmina-Gebergte , 5 Jun 1926, B. W. 6988 ( U) • In montibus Bakhuis inter flum. Kabalebo et Coppename Sinistruim , 30 Dec 1964, Florschütz and Maas 2577 ( U) . Venezuela. Delta Amacuro • Río Grande 37 km, este Noreste de El Palmar , 320 m, 10 Feb 1964, Steyermark 93135 ( F, NY, P, U, US, VEN) • El Palmar-Raudal trail 2–6 km SW of Río Ganame , 22 Nov 1955, Wurdack and Monachino 38715 ( US) . Zulia • Alrededores de la Represa Burro Negro , 12 Feb 1980, Bunting 8744 ( NY) . Yaracuy • Los Cañizos, plains of the Yaracuy river , 50 m, Jan 1920, Pittier 8758 ( NY, US) .

Figures

Figure 9. Thinouia myriantha Triana & Planch. A fertile branch B fruiting branch C immature fruits D cylindrical stem E cross-section of the simple stem F staminate flower G detail of inflorescence H detail of the margin and secondary veins [Acevedo-Rodríguez 17136 (B) 17128 (F) 14262 (G); Medeiros 3330 (A, C – E and H); photos: A, C, D, E, H by H. Medeiros B, F – G by P. Acevedo-Rodríguez].

Figure 10. Thinouia myriantha Triana & Planch. A flowering branch B leaf C portion of inflorescence, displaying a cincinnus and staminate flower D staminate flower E petal with bifid appendage, dorsal [abaxial] view F stamen of staminate flower G young fruit showing nectary disc H fruit I Mericarp J indumentum detail of locule cavity K capitate trichome with uniseriate stalk and unicellular terminal cells from locule cavity L capitate trichome with uniseriate stalk and multicellular terminal cells from locule cavity M simple trichome from locule cavity N seed O embryo (A – F from Costa 359 H – O from Medeiros 3330). Illustration by Maria Alice de Rezende.

Figure 13. Distribution maps of species from Thinouia A Thinouia cazumbensis and T. compressa B T. mucronata C T. myriantha D T. obliqua.