Myrceugenia nebulosa F.C.S.Vieira & L.D.Meireles, 2025

Myrceugenia nebulosa F.C.S.Vieira & L.D.Meireles , sp. nov.

TYPE:— BRAZIL. São Paulo: Campos do Jordão, São José dos Alpes, 22º43’33”S, 45º27’28”W, ca. 1899 m elev., 07 July 2023, F.C.S. Vieira & H. Lisboa 3631 (holotype USP!, GoogleMaps isotypes JOI!) GoogleMaps .

Figures 2 View FIGURE 2 , 4 View FIGURE 4 .

Diagnosis:— The species exhibits similarities to Myrceugenia cucullata D.Legrand (in Legrand 1957: 347, type image: PACA-AGP 4319; for description see Landrum 1981b: 72); however, the latter is characterized by dibrachiate trichomes, blades with approximately 20 secondary veins, and the apex of the sepal forming a structure similar to a horn, called a cucullus. In contrast, M. nebulosa possesses both simple and dibrachiate trichomes, 12–18 pairs of secondary veins, and sepals without a cucullus.

Description:— Tree 4–8 m tall; bark rough to fissured, whitish to gray in color, light beige on young branches; young branches flat with subglobose section; trichomes adpressed, sericeous-flaky on young branches and petioles, light brown, simple and dibrachiate, the dibrachiate ones with a short and triangular central axis and symmetrical arms. Leaves with petioles cylindrical on the abaxial side and slightly furrowed on the adaxial side, 4–8 × 1–2.2 mm; laminas chartaceous, narrow–elliptical, 35–60 × 14–20 mm, about 2.5 times as long as wide, light green on the abaxial surface and dark green on the adaxial surface, inconspicuous translucent glands visible under a magnifying glass, 1–3 per reticulum; base attenuate, apex acuminate, margin gently revolute, primary vein prominent on the abaxial surface and furrowed on the adaxial; secondary veins leaving the midvein at angles of approximately 45º, inconspicuous to the naked eye and barely noticeable even under a magnifying glass, around 12–18 pairs, more visible on the abaxial surface, not apparent on the adaxial surface; marginal veins inconspicuous, about 0.2– 0.6 mm from the edge. Flowers solitary, bracts absent; peduncles 3.2–4 × 0.4–1.2 mm, covered by simple and dibrachiate trichomes, beige to brown; bracteoles deltoid–triangular, 1.8–2.4 × 0.8–1 mm, internally concave and almost glabrous, externally covered by simple and dibrachiate, beige trichomes, and with the presence of a prominent rib, free at the base, inserted into the base of the ovary, not reaching the median portion of the flower bud; flower buds globose with petals visible; sepals triangular, 2.2–2.4 × 1.6–2.4 mm, with a rounded apex, covered by brown to beige trichomes externally, internally concave and with hyaline, simple and dibrachiate trichomes; petals white, orbicular, 3.6–5.6 × 3.2–5.2 mm, with sericeous, hyaline trichomes scattered on both sides, with some translucent glands evident; stamens 84–96, semi-curved in bud, 2.5 × 0.1 mm; style 5.2 × 0.3 mm, covered with sparse simple hyaline trichomes, stigma punctate; ovary trilocular, 7–9 ovules per locule, 23–25 ovules in total; fruits ellipsoid, 4–5 × 3–4 mm, darkened when mature.

Distribution, habitat and phenology:—This species is found in the municipalities of Camanducaia and along the Campos do Jordão Plateau, at the limits between the states of Minas Gerais and São Paulo, respectively, along the Mantiqueira mountain range, at elevations of around 1800–2000m in upper montane forests. It has been recorded flowering and fruiting from June to October.

Conservation status:—Some collections of this species were made in regions adjacent to the Campos do Jordão State Park, beyond the protected zone. Additionally, several specimens have been recorded from the Pedra do Selado region in Monte Verde, located within the municipality of Camanducaia. The analysis conducted using GEOCAT indicates that the species should be classified as Critically Endangered based on its extent of occurrence, (EOO= 30.879 km ²), and Endangered by area of occupation (AOO = 16 km ²).

Affinities: —This species is morphologically similar to Myrceugenia cucullata , with which it has often been confused in herbarium specimens. However, based on the criteria established in this study, M. cucullata is primarily a southern Brazilian species that can be distinguished by its approximately 20 secondary veins at each side. In contrast, M. nebulosa is endemic to the Mantiqueira mountain range and typically exhibits 12 to 18 pairs of secondary veins, in addition to the distinguishing features outlined in the diagnosis.

Etymology:—The specific epithet pertains to the challenges encountered in distinguishing this species over an extended period, thus denoting characteristics that are nebulous, vague, or uncertain. Additionally, it indicates the nebular environment in which the species is found, particularly in forested areas at elevated altitudes where orographic rainfall or fog frequently occurs.

Paratypes: — BRAZIL. Minas Gerais: Monte Verde, Camanducaia, Pedra do Selado , 28 June 2001, L.D. Meireles 315 ( UEC!) ; ibidem 28 June 2001, L.D. Meireles 341 ( UEC!) ; Monte Verde, Camanducaia , 29 June 2001, L.D. Meireles 383 ( UEC!) ; ibidem, 21 August 2001, L.D. Meireles, T.B. Breier & R. Belinello 463 ( UEC!); ibidem, 19 September 2001, L.D. Meireles, A. Flores, R.S. Rodrigues & R. Belinello 564 ( UEC!); ibidem, 19 September 2001, L.D. Meireles 565 ( UEC!); ibidem, 19 September 2001, L.D. Meireles 570 ( UEC!); ibidem, 19 September 2001, L.D. Meireles & B.Z. Gomes 1157 ( UEC!); ibidem, 19 October 2002, L.D. Meireles, C.F. Verola & I. Costa 1188 ( UEC!) ; São Paulo: Campos do Jordão, Estrada para São José dos Alpes, 21 June 1988, A. Furlan 526 ( UEC!). Idem , 07 July 2023, F.C.S. Vieira & H. Lisboa 3632 (JOI!, SPF!).