Hypenia hypoleuca Zavatin & Harley, 2025

Hypenia hypoleuca Zavatin & Harley , sp. nov.

(Figs. 1,2)

Type: — BRAZIL, Minas Gerais: Monte Azul, Serra das Marombas , 15° 8’ 34.8” S, 42° 47’ 31.2 W, 1100 m, 1 August 2024, D.A. Zavatin, F.R. de Sousa & V.A. de Sousa 2285 (holotype SPF!, GoogleMaps isotypes: BHCB, K, MEXU, P, RB). GoogleMaps

Diagnosis:— Hypenia hypoleuca differs from other species by the white canescent abaxial leaf surface and the corolla with 5–12 mm lenght.

Description:— Subshrub, up to 1.2 m. Stems erect, not odoriferous, hirsute, with setose trichomes below, and upper internodes glabrous, pruinose, fistulose, nodes swollen, this swelling with whitish indument, then sparse trichomes close to the node, young branches pubescent. Leaves simple, opposite, petiole 0.3–1.2 cm long, pubescent, leaf blade 1.2–3.3 × 1–2 cm, discolor, coriaceous, ovate, base cordate, or truncate, margin crenate, apex acute; adaxial surface tomentose-glandular, with simple tector trichomes, primary and secondary veins slightly apparent; abaxial surface canescent, primary vein apparent, ondulate, secondary veins slightly apparent, ondulate. Inflorescence thyrsoid, lax, main axis 7–20 cm long, glabrous and waxy, rarely pubescent; cymes 1–2, peduncle bracts 1–2 × 0.4–0.6 mm, filiform, apex acute, tomentose; peduncle 0.6–10 cm, sparsely pubescent with simple and glandular trichomes, bractlets of the pedicel 0.1–0.2 × 0.1 mm, filiform, apex acute, sparse trichomes; pedicel 2–8 mm long. with simple trichomes and glutinous trichomes. Flowering calyx vinaceous, deflexed, 3–5 mm long, campanulate, simple tector trichomes upon the venation, then glutinous on the surface; lobes 3 mm, symmetrical, broadly deltoid; Fruiting calyx declinate, 4–8 mm long, broadly campanulate, lobes 1,5– 2 mm broadly deltoid, throat glabrous. Corolla bilabiate, 5–12 mm long, tube 6–11 mm long, pinkish, internal surface glabrous, external surface with sparse glutinous trichomes, lobes ca. 3 mm long, middle anterior lobe hooded; stamens 4, 7 mm long, filaments pinkish, hirsute; style 12 mm long, pinkish, glabrous; ovary 4-lobate. Nucules sub-orbicular, 4 mm long, bluish when wet, then blackish.

Examined specimens (paratypes):— MINAS GERAIS. Monte Azul. Serra Montevidéu , Areinha branca, 15° 10’ 27.6” S, 42° 48’ 01.4” W, 1560 m, 26 April 2023, D.A. Zavatin, F.R. de Sousa & J.C.B. dos Anjos 1662 ( SPF!) GoogleMaps ; Pico da Formosa , 15° 14’ 01 S, 42° 49’ 9” W, 1538 m, 8 April 2022, M. Verdi, E.R. de Freitas, F. Saleme & L.A. Aragão 9076 ( RB1477778 ! HUEFS, SPF!). GoogleMaps Mato Verde. Na estrada para Montezuma, Serra do Mandaçaia , 15° 23’ 03” S, 42° 46’ 27” W, 1100 m, 17 March 1994, R.M. Harley, C.M. Sakuragui, P.T. Sano, N. Roque & V.C. Souza 15153 ( SPF97078 !) GoogleMaps .

Phenology: —Specimens were collected with flowers and fruits in April and August.

Etymology: —The epithet of this species comes from the Greek words ‘Hypo’ that means “Under” and ‘Leukós’ that means “white” in allusion to the white color of the abaxial surface of the leaves ( Stearn 2004).

Habitat and Distribution: — Hypenia hypoleuca is endemic to Minas Gerais state and occurs in the northern Espinhaço Range in the Campos Rupestres, between 1,100 and 1,560 m a.s.l. of elevation ( Fig. 3 View FIGURE 3 ). This region is the southern portion of the Brazilian semiarid, marked by savannah and xeric features, in the transition between the Cerrado, Campo Rupestre and the Caatinga. In the mountainous areas, the new species grows on rock outcrops or sand, where quartzite rocks predominate, which provides highly dystrophic substrates ( Fig. 3 View FIGURE 3 ).

Conservation status: — Hypenia hypoleuca occurs in a mountain range, and none of the subpopulations within protected areas ( Fig. 4 View FIGURE 4 ), with eventual and projected threats by inferred impacts that may cause habitat loss, which may compromise the long term persistence of the species ( Fig. 4 View FIGURE 4 ). Fire, one of the threats in the area evaluated, has a frequency of up to 10 times in the time series, equivalent to a minimum interval of 3.3 years between fires ( Fig. 5-B View FIGURE 5 ). However, this occurs punctually in restricted areas, and the frequency of fires is much lower or absent within the EOO. Infrequent and non-contiguous fires generally do not cause severe damage to the species. Among the main projected impacts is the expansion of quartzite mining, which is used for construction, flooring, panels, and countertops.Although there are no active mining areas in the EOO, recent progress has been observed in many of the processes for obtaining licence for mineral exploration ( Fig. 5-C View FIGURE 5 ). The research authorization and mining request stages precede the concession and subsequent exploration. All current records of H. hypoleuca are found in areas intended for mineral exploration, with three of the four occurrences located in areas where exploration concession applications are progressing through the licensing stages with the National Mining Agency.

Meanwhile, severe impacts that transform native vegetation into classes of anthropic land use are only observed south of the EOO ( Fig. 5-D View FIGURE 5 ). It should be noted that these change processes may increase as the licensing of wind farms intended for the region is consolidated, implementing the road infrastructure, transmission lines, and turbines necessary for the project. Considering the occurrences found in field collection activities and herbarium records, it was possible to calculate the AOO in 16 km 2 and the EOO in 48.82 km 2. Following mainly the geographic distribution criteria B1ab (i, iii, iv), it falls under the Critically Endangered (CR) status.

Similar species and Remarks: — Hypenia hypoleuca is morphologically similar to H. macrantha and H. reticulata mainly by the leaf shape and the corolla colour, however the species can be set apart from both species by the canescent indumentum on the leaf abaxial surface (vs. hirsute-tomentose in both species); the pedicel length 2–8 mm (vs 8–12 in H. macrantha and 10–20 mm in H. reticulata ); the corolla length 5–12 mm (vs. 18–22 mm in H. macrantha and 15 mm in H. reticulata ); the stamen length 7 mm (vs 10 mm in H. macrantha and 16 mm in H. reticulata ) and the style length 10– 10 mm (vs. 20–24 mm in H. macrantha and 20 mm in H. reticulata ). These and other compared characters are summarised in Table 1 View TABLE 1 .