Ancistrotropis pulchra F.S.Santos, Snak & L.P.Queiroz, sp. nov. (Figs. 1, 2A, B, D–F)

Type:— BRAZIL, Minas Gerais, Alto Caparaó, Parque Nacional do Caparaó; estrada entre a entrada da Cachoeira Bonita e o Mirante da Tronqueira, 1950 m. elev., 20°24ʹ30.6ʹʹS 41°50ʹ16.4ʹʹW, 31 January 2024, F.S. Santos, A. Fonseca-Cortés, J.F.C. Oliveira & M. Macário 149 (Holotype: HUEFS barcode HUEFS000100277448; Isotypes: K, MEXU, RB).

Diagnosis:— Ancistrotropis pulchra resembles A. robusta by its twining habit and pink flowers of similar size and coloration, but differs by the whitish to slightly yellowish indumentum on stems, petioles, rachis, and inflorescences (vs. densely tomentose and predominantly ferruginous in A. robusta), leaflets, 4–8 × 1.7–3.5 cm, concolorous and sparsely sericeous to glabrescent (vs. 6.1–11.6 × 4.3–7.5 cm, discolorous and pubescent to tomentose), more numerous inflorescences per branch, each usually bearing three or more flowers open simultaneously (vs. fewer inflorescences, each typically with only one to two flowers open), and patent fruit in the inflorescence rachis (vs. erect).

Twining vine, with green branches when young, sparsely pubescent to pubescent. Stipules 1.8–3.1 × 1.6–2.3 mm, triangular, apex acute, base truncate, glabrous. Leaves trifoliolate; petiole 1.6–6.2 cm long, rachis 0.6–0.9 cm long, canaliculate, pilose; stipels 0.8–1.4 mm long, subulate; leaflets papyraceous to chartaceous, apex acute, mucronate, pinnately veined, secondary veins 6 pairs, brochidodromous, upper and lower surface glabrescent to sparsely sericeous; lateral leaflets 4.1–7 × 1.7–3.5 cm, lanceolate to ovate, asymmetrical, base rounded; terminal leaflets 5.4–8 × 1.8– 3.5 cm, lanceolate, lanceolate-elliptic, elliptic to ovate, base cuneate to rounded. Inflorescence an axillary nodose pseudoraceme, with a small pair of bracts near the base of the peduncle, peduncular bracts 1.9–2.7 mm long.; peduncle 5.1–12 cm long, pilose to pubescent; rachis 3–8 cm long, pubescent, nodosities globose to elongate; pedicels 1.52– 2.62 mm long; bracteoles 2.2–2.86 mm long, obovate to oblong, glabrous to glabrescent, caducous. Flowers 26–26.5 × 26.1–26.2 mm, with the length almost equal to the width when the flower is open; calyx green with vinaceous blotches, the tube c. 3 × 6 mm, campanulate, pubescent on the outer surface, 4-toothed, vexillary tooth (two fused), 2.4–2.5 mm long, depressed ovate, apex rounded, lateral teeth 2.4–2.5 mm long, carinal tooth 2.6–2.8 mm long, both triangular, apex acute; Petals pink; standard petal c. 21 × 27 mm, widely depressed ovate, apex retuse, callosity absent, papillae in the centre of the lamina toward the base of the claw, auricles hook-shaped c. 3.5 mm, with membranaceous extensions perpendicular to the centre of the blade, claw c. 3 mm long; wing petals c. 27 × 17 mm, slightly overlapping between themselves, the left wing petal positioned inclined above the right one, lamina with the middle portion expanded, apex rounded, pocket in the inner face absent, base with a rounded spur, claw c. 5.8 mm long; keel petals perimeter c. 20 mm long, rostrum 17.5 × 10 mm, sigmoid, extending in curved hook-shaped beak above 90°, the two petals connected by conspicuous interlocking marginal trichomes along the adaxial (inner) margin, trichomes 0.2–0.3 mm, claw c. 4.9 mm long; androecium c. 34 mm long, diadelphous, nine stamens joined in a sheath and the vexillary stamen free, the base of the filament of the free stamen with a triangular and fleshy protuberance, stamens at different heights, anthers dorsifixed; gynoecium with ovary c. 10.6 × 1 mm, sessile, pubescent; style c. 20.9 mm long, the apex arching outwards and flattened, stigma lateral, capitate, brush of hairs encircling the entire stigma and part of the apex of the style, nectary ring at the base of the ovary. Fruit a legume, c. 82 × 32 mm, linear, cylindrical, apex acuminate, patent on the inflorescence rachis; valves rigidly coriaceous, with small depressions between the seeds, pubescent. Seeds not seen.

Etymology: —The specific epithet pulchra derives from the Latin pulcher (“beautiful” or “charming”) and alludes to the conspicuous and abundant flowering of the species, characterised by the simultaneous production of numerous inflorescences and flowers.

Flowering and Fruiting: —The species was collected in flower and immature fruit in January.

Distribution: — Ancistrotropis pulchra is known only from the protected area of Parque Nacional do Caparaó, on the border between the states of Espírito Santo and Minas Gerais, Brazil. It occurs in high-altitude grasslands near cliff edges, at around 1,900 metres elevation, in an environment associated with the Atlantic Forest.

Conservation status: — Ancistrotropis pulchra is a rare species with an extremely restricted occurrence within Parque Nacional do Caparaó. During extensive surveys conducted along the park’s trails and roads, only a single individual was recorded, highlighting its very low population density. In addition, there is only one previous collection record of this species, dating back to 2001, representing a gap of 23 years without new records of similar individuals in the area. Both occurrences are associated with high-altitude grasslands above 1,900 metres elevation.

Based on this extremely limited distribution and low population size, A. pulchra qualifies as Critically Endangered (CR) under the IUCN criteria, specifically under criterion D. Criterion D reflects the presence of an extremely small population (fewer than 50 mature individuals). The new species is affected by a high risk of extinction due to the very restricted area of occupancy and the potential impact of events that could rapidly drive the species to extinction, such as wildfires, climate change, or human activities affecting the integrity of high-altitude grassland ecosystems. Therefore, more in-depth field research is necessary to better evaluate the conservation status of the new species, also considering that newly described species are attributed to very different IUCN categories, ranging from more severe threat categories (e.g. Moraes et al. 2014; Brullo et al. 2015; Fenu et al. 2016; Orsenigo et al. 2016; Pereira et al. 2016; Stinca et al. 2019; Andrade & Freitas 2021; Ben Mahmoud et al. 2024), through near threatened (Perrino et al. 2018) or even least concern (Siti-Munirah & Dome 2023).

Notes: — Ancistrotropis pulchra is restricted to high-altitude grasslands and is distinguished by its twining habit, with green, pubescent branches; leaflets elliptic to ovate, concolorous, chartaceous, the abaxial and adaxial surfaces glabrescent to sparsely sericeous; numerous inflorescences and open flowers along its branches; and lilac-coloured flowers.

Additional specimens examined (Paratypes):— BRAZIL, Minas Gerais, Alto Caparaó, Parque Nacional do Caparaó; surge ao lado da estrada, 1990 m. elev., 05 May 2001, L.S. Leoni 4660 (RB barcode 01339454).