Thinouia tomocarpa Standley
Creators: name: Medeiros, Herison
name: Acevedo-Rodríguez, Pedro
name: de Carvalho Lopes, Jenifer
name: Forzza, Rafaela Campostrini
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Sapindales
Sapindaceae
Thinouia
Thinouia tomocarpa

description: 11.Thinouia tomocarpaStandley, Field Mus. Nat. Hist., Bot. Ser. 12: 411. 1936
Figs 19 C, 22
Type.
Belize • Temash River, 6 Feb 1935, W. A. Schipp 1336 (holotype: F [0361405 F] [image!], isotypes: G [G 00008257] [image!], G [G 0008262] [image!], G [G 00008260] [image!], G [G 00008261] [image!], MICH [MICH 1115487] [image!], K [K 000634088] [image!], NY! [NY 00387405], S [S-R- 11015] [image!]).
Description.
Tendrilled liana; stems cylindrical, striate, tomentose to glabrescent, lenticels round or elliptical; cross-section simple. Leaves trifoliolate; stipules minute, <0.5 mm long; petiole ca. 4.8 cm long, terete, puberulous; terminal petiolules 2–2.2 cm long, canaliculate; lateral petiolules 0.8–1 cm long; leaflets glabrous on both surfaces; leaflet secondary venation semicraspedodromous to eucamptodromous, secondary veins 4–6 pairs, alternate, spacing irregular, domatia wanting; intersecondaries present; margins repand-serrate, sometimes only at the apex, with (2) 4–6 teeth on each side, reduced to inconspicuous glands; terminal leaflet 6–8 × 5 cm, elliptic or oblong-ovate, sometimes asymmetrical, the apex long-apiculate or obtuse, the base rounded to obtuse; lateral leaflets 6.5 × 3.9–4.2 cm, elliptic or ovate, sometimes asymmetrical, the apex long-apiculate or obtuse, with a gland at the apex, the base truncate to rounded. Thyrses axillary or terminal, umbelliform, 3.5–6 cm long; peduncle 1.8–3.6 cm long; secondary peduncle sessile or 0.1–0.7 cm long; cincinni numerous, peduncle of cincinnus 2–5 mm long, tomentose. Flower 3–4 mm long, pedicel 1.9–2.4 mm long, tomentose; sepals ca. 0.7 mm long, deltate, abaxially villous and adaxially glabrous; petals 0.6–1.3 mm long, obdeltate, not clawed, villous; appendages 1.4–1.6 mm long, longer than the petals, bifid, marginal, villous; nectary disc annular to slightly lobed, glabrous. Staminate flowers with stamens 8, ca. 4 mm long, the filaments villous throughout, the anthers sparsely villous; pistillode ca. 1 mm long, tomentose. Pistillate flowers with staminodes 8, ca. 2 mm long, villous throughout, the anthers sparsely villous; pistil 1.2–1.4 mm long, villous, the ovary villous, the stigma and style villous. Fruits chartaceous, 3–8 × 1.7–4 cm; accrescent pedicel 2.4–3.8 mm long; stipe ca. 4.3 mm long; seed locule subglobose, but flattened at the base, sometimes slightly flattened, puberulous; seed locule cavity densely covered with capitate trichomes; these with uniseriate stalk and unicellular terminal cells. Seed ellipsoid, 2.5–3.5 × 1.5–2 mm, basally attached.
Distribution and habitat.
This species is known from southern Mexico (Chiapas & Veracruz), the Yucatan Peninsula in Mexico (Campeche, Quintana Roo) and Belize and in El Salvador, in tropical and subtropical moist broadleaf forests at 120–830 m elevation (Fig. 19 C). Flowering from February to April, and fruiting from April to May.
Notes.
Thinouia tomocarpa was described by Standley and Record (1936) based on the morphology of the fruit, which appeared as if its apex has been cut off by shears, hence the name tomocarpa [from the Greek word tomus, meaning ‘ cutting’]. This species is otherwise very similar to T. myriantha. Although Croat (1976) lumped T. tomocarpa in the synonymy of T. myriantha, we are resurrecting it because (1) morphologically, T. tomocarpa and T. myriantha are differentiated by the stamens which are villous throughout in the former but villous only on the lower half in the latter (2) petal appendage is marginal in T. tomocarpa (vs. basal); and (3) in our molecular phylogenetic studies show that samples representing T. tomocarpa form a monophyletic group with very strong support which is sister to a clade containing T. myriantha and T. silveirae (Fig. 4).
Conservation status.
Thinouia tomocarpa possesses an EOO of 227,986.147 km 2 and an AOO of 56.00 km 2, with more than 10 known locations. The EOO values and the number of threatening situations approach the thresholds for classifying the species in a threat category. Beyond this, there are no data on population declines for the application of other criteria, thus it should be regarded as Least Concern (LC).
Selected specimens examined.
Belize. Cayo • Chiquibul Forest 4 km on the road from Las Cuevas, 12 Apr 2003, MacMaster et al. 12 (MEXU). El Salvador. La Libertad • Laderas de La Laguna, 6 May 1987, R. Cruz 44 (MEXU). Mexico. Campeche • Mun. Calakmul, 7.5 km al W de Flores Magón, 175 m, 12 Mar 2002, Soto et al. 22768 and 22770 (MEXU) • Mun. Hopelchén, a 3 km al N de Zoh-Laguna camino a Dzibalchén, 200 m, 1 Apr 1996, Alvaro and Martínez 268 (MEXU, MO). Chiapas • Mun. Ocosingo, Ribera del río Chajulillo al sur de la Estación, 22 Feb 199, Colín 2369 (MEXU) • Mun. Palenque, near side road to Agua Azul 0 km South of Palenque, 13 Apr 1981, Breedlove 50858 (MEXU). Quintana Roo • 18 km sobre camino a Tomas Garrido, 8 May 1980, Téllez and Cabrera 2134 (MEXU) • 3 km al sur de La Pantera, por la vía corta a Mérida, 21 Mar 1981, Cabrera 1672 (MEXU) • 12 Km al N de San Felipe Bacalar, 22 Mar 1983, Cabrera 4530 (MEXU, NY) • Mun. Jóse María Morelos, a 11.9 km al SE de La aguada La Presumida, 150 m, 12 Mar 2004, Álvarez et al. 8113 (MEXU) • Mun. Othón P. Blanco, La Pantera, 10 Apr 1998, Granados and Chí 641 (MEXU). Veracruz • Mun. San Andrés Tuxtla, Estación de Biología Tropical Los Tuxtlas, 27 Mar 1983, Manriquez 495 (MEXU, NY).
description: Published as part of Medeiros, Herison, Acevedo-Rodríguez, Pedro, de Carvalho Lopes, Jenifer & Forzza, Rafaela Campostrini, 2025, Taxonomic revision and phylogenetic relationships of Thinouia (Sapindaceae), a neotropical genus, pp. 207-273 in PhytoKeys 252 on pages 207-273, DOI: 10.3897/phytokeys.252.129621