Huberia mayarae Bochorny & R. Goldenb., 2025

Bochorny, Thuane, Gonella, Paulo M., Gonçalves, Lucas N., Völtz, Rafael R. & Goldenberg, Renato, 2025, Five new species of Huberia (Melastomataceae) from the eastern Brazilian mountains, Plant Ecology and Evolution 158 (1), pp. 23-42 : 23-42

3. Huberia mayarae Bochorny & R. Goldenb. sp. nov.

Figs 3 , 6 , 7

Type.

BRAZIL – Minas Gerais • Marmelópolis, Pico dos Marins ; 22°29’47.68”S, 45°7’38.33”W; 2100 m; 28 Nov. 2020; Gonçalves L. N. 635; holotype: UPCB; isotype: RB .

Diagnosis.

Huberia mayarae differs from Huberia organensis (Saldanha & Cogn.) Bochorny & R. Goldenb. due to the leaves with a rounded apex, subcordate base, and adaxial and abaxial surfaces glabrous (vs an acute apex, obtuse or rounded base, and abaxial surface covered with dendritic trichomes), 5–6 - merous flowers, on pedicels 5–10 mm long (vs 6 - merous, on pedicels 2–3.5 mm long); hypanthium 4–7 × 3.5–5 mm, densely covered with stalked glands (vs 2–3 × 2–3.5 mm, glabrous); sepals ca 1 × 0.5 mm, ciliolate margin (vs 0.3–0.5 × ca 0.2 mm, not ciliolate); petals with an apiculate apex (vs not apiculate).

Description.

Shrubs 0.2–0.5 m tall; branches, petioles, inflorescences, bracts, and bracteoles densely covered with both short and stalked glands (these up to 2 mm long, the heads sometimes caducous). Branches terete, striate. Leaves opposite; petiole 0.4–1.7 cm long; blade 2.3–5 × 1.6–3 cm, ovate or broadly elliptic, apex acute, base subcordate, margin serrulate and eciliolate, papyraceous, adaxial and abaxial surfaces glabrous, acrodromous veins 3, with an additional faint submarginal pair, basal, main veins impressed adaxially and raised abaxially, transverse veins and reticulation visible on both surfaces. Inflorescences thyrsoids or compound dichasia 4.5–6 cm long, terminal, with 10 flowers; bracts two, persistent, leafy, petiole ca 6 mm long, blade ca 30 × 15 mm, ovate or broadly elliptic; bracteoles two, persistent, ca 1 mm long, ovate. Flowers 5–6 - merous, on pedicels 5–10 mm long. Hypanthium 4–7 × 3.5–5 mm, campanulate, densely covered with stalked glands 0.5–1 mm long; torus glabrous. Calyx tube 0.5–1 mm long, densely covered with stalked glands ca 1 mm long; sepals ca 1 × 0.5 mm, triangular, apex apiculate, margin ciliolate ca 0.5 mm long (the purple cilia sometimes caducous); external teeth absent. Petals 7.5–15 × 4.5–7 mm, white, obovate and asymmetric, apex acuminate and apiculate, margin entire, adaxial and abaxial surfaces glabrous. Stamens 10–12, subisomorphic, glabrous; filaments 8.5–10.5 mm long (antesepalous) or 8.5–9.5 mm long (antepetalous), greenish; connective not prolonged below the thecae, dorsal appendages ca 3 mm long, yellow, linear-subulate; anthers 4–4.5 mm long in both cycles, yellow, oblong-linear, the thecae prolonged up to 0.2 mm below the insertion of the filament, with a single, apical (but ventrally inclined) pore. Ovary ca 3 mm long, 2 / 3 basally adhered to the hypanthium, 4 - locular, apex without lobes, glabrous; style ca 9.5 mm long, slightly curved or sigmoidal, glabrous. Capsules ca 8.5 × 6.5 mm, the carpels exceeding the hypanthium length by ca 1 mm; seeds not seen.

Distribution and habitat.

Huberia mayarae has been found growing in small crevices or directly on the surface of rock walls near the summit of the Pico dos Marins, in the Serra da Mantiqueira mountains, located on the border between the states of Minas Gerais, Rio de Janeiro, and São Paulo (Fig. 3 C ). The plants were collected at 2100 m elevation (while the summit is at 2420 m), right on the border between Minas Gerais and São Paulo but just a few meters on the Minas Gerais side. It also occurs in São Paulo (Lucas N. Gonçalves pers. obs.), but it has not been collected there. The rock outcrops are surrounded by Montane Atlantic Rainforest (Fig. 3 A ).

Phenology.

Collected with flowers and fruits in November.

Etymology.

The epithet honours the botanist Dr Mayara Krasinski Caddah, now at Universidade Federal de Santa Catarina. Dr Caddah has contributed to the knowledge of Melastomataceae in Brazil, mostly on taxonomy, morphology, and phylogeny of Miconia Ruiz & Pav. in the Brazilian Amazon and the Atlantic Forest.

Preliminary IUCN conservation assessment.

Data Deficient: DD. Huberia mayarae has an AOO of 4 km 2 (EOO cannot be calculated as there are only two records) and was only recorded outside the Monumento Natural Estadual da Mantiqueira Paulista, a full protection conservation area. Despite the restricted range, no threat was observed affecting the known population of the species. The region is visited by many tourists yearly, yet the plants were observed away from the trail. Given the lack of information on population size and uncertainty about its entire distribution, we preliminarily assess this species as Data Deficient.

Additional material studied (paratype).

BRAZIL – Minas Gerais • Marmelópolis, Pico dos Marins, 2 ° maciço ; 22°29’48”S, 45°07’44”W; 2100 m; 19 Oct. 2020; Gonçalves L. N. 472; CESJ .

Notes.

Huberia mayarae is morphologically similar to H. organensis since both have papyraceous leaves, thyrsoids 4.5–6 cm long, petals with both surfaces glabrous, and glabrous torus. Apart from the differences pointed out in the diagnosis, the trichomes are dendritic in H. organensis , while the stalked glands in H. mayarae are unbranched, larger (both short and stalked glands, these up to 2 mm long), with globular gland heads (the heads sometimes caducous). Huberia organensis occurs at Reserva Biológica de Araras, in Petrópolis, Rio de Janeiro, which is about 200 km in a straight line from where H. mayarae was collected.

Huberia mayarae is also similar to H. rubricalyx . For a comparative overview, see Table 2 .

Figures

Figure 3. Geographical distribution of the new species in the eastern Brazilian mountains (A), in the states of Minas Gerais (B), São Paulo (C), and Rio de Janeiro (D). ES: Espírito Santo; MG: Minas Gerais; RJ: Rio de Janeiro; SP: São Paulo.

Figure 6. Photos of Huberia mayarae in the field (by Lucas N. Gonçalves). A. Frontal view of a flower. B. Detail of the stamens and style. C. Fruits. D. Habit. E. Leaf (adaxial view). F. Habitat. G. Branch with an inflorescence.

Figure 7. Images from the holotype of Huberia mayarae (Gonçalves L. N. 635, UPCB). A. Branch with inflorescences. B. Detail of the stem indumentum. C. Leaf (adaxial surface). D. Leaf (abaxial surface). E, F. Detail of the leaf glabrous surfaces. G. Detail of the leaf margin. H. Flower. I. Flower bud. J. Petal (adaxial surface). K, L. Stamens. M. Style. N. Fruit.