Lippia raoniana P. H. Cardoso & Salimena, sp. nov.

Lippia raoniana P.H.Cardoso & Salimena sp. nov.

urn:lsid:ipni.org:names:77214745-1

Figs 1, 4 B–C

Diagnosis

The new species is similar to Lippia spiraeastrum (Mart. & Schauer) T.R.S.Silva, but differs by ovate leaves (vs oblong or oblong-elliptic), slightly discolorous (vs strongly discolorous), matte adaxial surface (vs shiny), glandular abaxial surface (vs tomentose-glandular), shorter peduncle (0.8–1.3 vs 3.2–10.5 cm long) and slender (vs thick), ovate bracts (vs lanceolate).

Etymology

The specific epithet is in homage to Raoni Metuktire, an important indigenous leader of Brazil, internationally known as a symbol of environmental preservation. Raoni is dedicated to the fight for the rights of native indigenous people and conservation of the tropical forest, mainly Amazonia. His legacy is a symbol of the daily struggle for Brazilian biodiversity, constantly threatened.

Material examined

Type BRAZIL – Minas Gerais • Serro, “ próximo ao Km 1 do distrito de Milho Verde” [near to Km 1 of the Milho Verde district]; 18°27′35.1″ S, 43°29′24.4″ W; 13 Feb. 2020; fl / fr; F.R.G. Salimena & P.H. Nobre 4057; holotype: CESJ; isotypes: HUEFS, RB, SPF.

Paratypes BRAZIL – Minas Gerais • Felício dos Santos, “ APA Municipal Felício ” [Municipal Environmental Protection Area Felício]; 10 Jun. 2006; fl / fr; F.R.G. Salimena et al. 1382; CESJ • Serro, “ estrada Diamantina para o distrito de Milho Verde ” [road from Diamantina to the Milho Verde district]; 16 Nov. 2010; fl / fr; V. Thode, P. Lu-Irving, N. Mota, M. Toledo 386; CESJ, ICN.

Description

Shrub 1.5 m tall, aromatic, branched, branches erect, tetragonal, sulcate, glabrescent to strigose, with sessile glandular trichomes, nodes conspicuous. Leaves decussate, patent, congested at the stem apices, petioles 2.2–6 mm long, cylindrical, strigose, with abundant sessile glandular trichomes; blades 1.5–3 × 0.8–1.5 cm, chartaceous, ovate, slightly discolorous, apex acute to obtuse, base cuneate, decurrent into the petiole, margin basally entire, crenate to serrate toward the apex, ciliate, slightly revolute, adaxial surface matte, sparsely strigose, densely covered by sessile glandular trichomes, abaxial surface densely covered by sessile glandular trichomes, strigose along the veins. Inflorescence one per axil, 0.5–1 cm long, capituliform, hemispherical, rachis not elongated in the infructescence, peduncle 0.8–1.3 cm long, cylindrical, slender, strigose, with abundant sessile glandular trichomes; bracts 3–5 mm long, green, spirally arranged, ovate, apex acute to obtuse, margin ciliate, adaxial surface strigose, covered by sessile glandular trichomes, abaxial surface densely covered by sessile glandular trichomes; calyx 1–2 mm long, tubular, 2-lobed, apex 4-toothed, externally hirsute, ciliate, with abundant glandular sessile trichomes; corolla tube 6–8 mm long, limb 2-labiate, lilac, hypocrateriform, externally pubescent, with abundant glandular sessile trichomes, throat yellow, pubescent, 4 didynamous stamens, inserted at the middle of the corolla tube, included, thecae parallel; ovary 1 mm long, ovoid, glabrous, 2-locular, 1 ovule per locule, stigma oblique, lateral. Fruit drupaceous, mesocarp dry, 2-pyrenate, 2 mm long, spherical, lightbrown, dorsal surface smooth to slightly striated, surrounded by the persistent calyx.

Distribution, habitat and phenology

Lippia raoniana P.H.Cardoso & Salimena sp. nov. is known only from two localities in the Diamantina Plateau (Felício dos Santos and Serro), on the Espinhaço Range, Minas Gerais, Brazil, where it seems to be endemic (Fig. 2). The populations are quite small and grow on quartzitic rock outcrops (campos rupestres), at an elevation of 1200–1400 m. Plants were collected with flowers and fruits in January, June, and November.

Prelimiminary conservation status

Lippia raoniana P.H.Cardoso & Salimena sp. nov. is only known from two localities, presenting an estimated Area of Occupation (AOO) smaller than 10 km ². The first known population is small and located in the municipality of Serro, along an unpaved road, near to a residential area under urban pressure. The other population is recorded from the municipality of Felício dos Santos, inside a conservation unit. The Diamantina Plateau is now witnessing increasing, uncontrolled tourism, exposing the vulnerability of its soils and vegetation (Schaefer et al. 2002). Thus, L. raoniana sp. nov. may be considered Critically Endangered (CR) based on criteria and sub-criteria B2ab(ii, iii, iv) of IUCN (2019), due to its restricted AOO, number of known locations, and the continuous decline in the quality of its habitat.

Notes

Lippia raoniana P.H.Cardoso & Salimena sp. nov. most closely resembles L. spiraeastrum, which is also endemic to the Espinhaço Range, occurring in Gr„o Mogol, Minas Gerais State (Salimena & Cardoso 2020), due to the shrubby habit, conspicuous nodes, leaves concentrated in the upper portion of the stem, adaxial surface glandular, axillary inflorescences, capituliform, hemispherical, corolla lilac, and fruit with dry mesocarp, 2-pyrenate. However, several characters of the leaves, peduncles and bracts can be used to distinguish them. The new species is mainly characterized by the combination of ovate leaves with adaxial and abaxial surfaces densely covered by sessile glandular trichomes, peduncles 0.8–1.3 cm long, and ovate bracts with adaxial and abaxial surfaces densely covered by sessile glandular trichomes.