Eugenia pachymarginata Campelo, M.C.Souza & J.M.A.Braga, sp. nov.

Type:— BRAZIL. Rio de Janeiro: Nova Iguaçu, Parque Natural Municipal de Nova Iguaçu, Pedra da Contenda, 428 m, 22˚46ʹ35ʹʹS, 43˚28ʹ17ʹʹW, 20 May 2025, fl., M.V. Campelo, G.S. Guimarães & L. Oliveira 81 (holotype RB 886666 [two sheets]!; isotypes RBR!, UB!).

Figures 1–3.

Diagnosis: — Eugenia pachymarginata is morphologically similar to E. malacantha D. Legrand (1961: 324) and E. culicina in their fasciculate inflorescences (umbel-like, lacking a central axis), but differs from the former by its petioles 12–20 mm long (vs. 1.2–7.6 mm long in E. malacantha), fruits globose (vs. oblate to ellipsoid) with a single seed (vs. 2–4), and with a smooth surface (vs. verrucose). Compared to E. culicina, it is also distinguished by the petiole length (12–20 mm vs. 2–5 mm in E. culicina), stamens with filaments ca. 5.5 mm long (vs. 7–8 mm long), flowers externally tomentose (vs. pubescent), and mature fruits ca. 22 × 25 mm (vs. 45–60 × 35–65 mm), with smooth surface (vs. muricate or rugose). Additionally, E. pachymarginata can be distinguished from both species by the marginal vein almost continuous (vs. in prominent arches).

Description:—Shrubs to trees 2–7 m tall, cespitose. Trunk with bark brownish-grey, accumulated rhytidome, detaching into small, thin and irregular shape plates. Branches cylindrical, canescent when young, becoming glabrescent. Leaves with petioles 12–20 × 2.5–2.8 mm, glabrous, canaliculate adaxially; blades 125–150 × 60–78 mm, elliptic, base cuneate, apex rounded or retuse, chartaceous, bright green adaxially, dull green abaxially, margin thickened, glabrous adaxially, sparsely pubescent abaxially, 4–7 glandular dots per mm², midvein canaliculate adaxially, prominent abaxially, glabrous on both surfaces, secondary veins 12–14 at each side, visible on both surfaces, diverging from the midvein at 57–60 degrees, marginal veins 2, almost continuous, the inner one ca. 2.5 mm from the margin, the outer one ca. 1 mm from the margin. Inflorescences in fascicles, terminal, with a white to ferruginous, tomentose indumentum, bearing 4–6 decussate flowers, rachis reduced and almost indistinguishable; bracts 2.5–3 × ca. 1.5 mm, elliptic, apex acute, greenish, ferruginous tomentose; bracteoles ca. 4 × 1 mm, filiform, apex acute, greenish, externally ferruginous tomentose, internally glabrous, deciduous after anthesis. Floral buds 7–11 × 5–10 mm, obovoid, tomentose, greenish to white, drying with ashy or ferruginous tones. Flowers with pedicels 3–6.5 × 1.4–1.8 mm, greenish to brownish, tomentose; hypanthium 2.5–3 mm long, greenish to whitish, ferruginous tomentose; calyx lobes 4, in two unequal pairs, elliptic, green, 2 lobes ca. 2.5 × 5 mm, apex rounded, 2 lobes ca. 4 × 6 mm, apex acuminate; petals 4, ca. 9 × 9 mm, orbicular, apex rounded, white, or cream to yellowish in senescence, glabrous, reflexed; stamens ca. 190; filaments ca. 5.5 mm long, white, yellowish in senescence; anthers ca. 0.5 mm in diameter, globose, yellow; staminal disk ca. 5.2 mm in diameter, ca. 1.8 mm thick, white, puberulent; style ca. 7 mm long, white, glabrous; stigma punctiform; ovary 2-locular, with 14 ovules per locule, glabrous. Fruits ca. 22 × 25 mm, globose, smooth, velutinous, green (immature) or yellow (mature); seed 1, ca. 20 × 20 mm, globose, yellow, surface not adhered to the endocarp, lignified testa, cotyledons fused, linear hilum.

Distribution and conservation status: —The species is presently known only from the Metropolitan Region of the Brazilian state of Rio de Janeiro, in the municipality of Nova Iguaçu (Figure 4), at elevations of 200– 400 m. To date, there are only five collections of this species, all from the same protected area, the Parque Natural Municipal de Nova Iguaçu, part of the Gericinó-Mendanha Massif. Considering the presently known occurrence records, the Extent of Occurrence (EOO) of the species is only 0.262 km ², a notably small area. Possible threats to the habitat are the ongoing urban expansion and increasing real estate speculation in the surrounding areas. Additionally, despite its occurrence within a conservation unit, the proximity to expanding urban zones makes it susceptible to habitat degradation, edge effects, and potential pressure for land-use changes. Based on these factors, the species is here assessed as Critically Endangered (CR) under the criteria CR B1ab(i,ii,iii) from IUCN (2012).

Phenology: —Flowering in May, July and August; fruiting in September and November.

Etymology: —The specific epithet refers to the characteristic thickening of the leaf margin (Figure 3A), a feature that occurs in other species of the group but is particularly prominent feature in this species compared to its close relatives.

Paratypes:— BRAZIL. RIO DE JANEIRO: Nova Iguaçu, Parque Natural Municipal de Nova Iguaçu, Córrego a direita, na estrada principal, 22°46’52”S, 43°27’40”W, 202 m, 25 September 2024, fr. imat., M.V. Campelo & G.S. Guimarães 54 (RB!); ibid., Mar de Bromélias, trilha do Pau Pereira, 22°46’55”S, 43°28’08”W, 234 m, 19 July 2024, fl., M.V. Campelo & G.S. Guimarães 37 (RB!); ibid., 3 August 2024, fl., M.V. Campelo & G.S. Guimarães 42 (RB!); ibid., 27 November 2024, fr., M.V. Campelo, G.S. Guimarães & J.M.A. Braga 64 (RB!, RBR!); ibid., 13 July 2007, fl., R. Moura et al. s.n. (RBR 44917!).

Taxonomic notes: —The linear bracteoles that are deciduous after anthesis, fruits larger than 2 × 2 cm, velutinous and yellow when mature, ovary with internally glabrous locules, and fused cotyledons were relevant characters for circumscribing the species within Eugenia subg. Pseudeugenia. Within this subgenus, E. pachymarginata is related to a group of species characterized by fasciculate inflorescences, tomentose flower buds, and an indumentum ranging in color from whitish to cream, brown, or rusty, as observed in E. gomesiana O. Berg (1857: 254), E. incanescens Bentham (1840: 321), and E. culicina (Maruyama in prep.).

A notable feature in this subgenus is the vegetative proliferation of the inflorescence axis (Mazine et al. 2018), although well-developed racemose or even fasciculate inflorescences, as mentioned previously, can also occur (Maruyama in prep.). The absence of this characteristic inflorescence type can be seen in E. pachymarginata, as well as in E. malacantha, E. culicina, and E. serraegrandis Sobral (in Sobral et al. 2012: 32).

Vegetatively, E. pachymarginata resembles E. altissima Sobral & Faria (in Sobral et al. 2015: 204), especially by the leaves larger than 125 mm, with a rounded apex and cuneate base, and both species exhibit an accumulation of rhytidomes in the bark. However, while E. altissima exhibits a dense indumentum on the abaxial leaf surface, E. pachymarginata differs by having only a sparse indumentum covering. In relation to leaf length, it is noteworthy that other species also possess blades exceeding 100 mm, such as: E. bragae T.Fern. & Faria (in Fernandes & Faria 2022: 194), E. culicina, Eugenia rugosissima Sobral (2006: 74) and E. serraegrandis. The thickening of the leaf margin also occurs in E. klotzschiana O. Berg (1857: 255), from the Cerrado (Brazilian savanna), but this species presents a dense indumentum on the abaxial leaf surface (sparsely pubescent in E. pachymarginata), larger floral buds (7–11 vs. 10–16 mm long in E. klotzschiana) and pyriform fruits (vs. globose in E. pachymarginata). For comparison purposes, some species of the E. subg. Pseudeugenia were analyzed, which is presented in Table 1.