Microlicia xanthopetala Versiane & R. Romero 2025, sp. nov.
Creators: name: Romero, Rosana
name: Pataro, Luciano
name: Versiane, Ana Flavia A.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Melastomataceae
Microlicia
Microlicia xanthopetala

description: 3.Microlicia xanthopetalaVersiane & R. Romero sp. nov.
Fig. 5, Supplementary material 3
Type
BRAZIL – Bahia • Mucugê, Trilha para o Morro da Tesoura; 13°01’07”S, 41°22’52”W; 960–1000 m; 16 Aug. 2005; fl., fr.; A. K. A. Santos, E. C. Oliveira, S. F. Rocha, et al. 449; holotype: HUEFS!; isotype: HUFU! [HUFU 00064429].
Diagnosis
Microlicia xanthopetala is similar to M. aurea. However, it differs in having branches, leaves, and hypanthium covered with setose trichomes mixed with spherical glands (vs only spherical glands in M. aurea), narrowly elliptic leaf blades (vs lanceolate-elliptic), and linear sepals (vs triangular).
Description
Shrubs, erect, branched, ca 0.4 m tall. Younger and older branches terete, brownish, densely covered with setose trichomes mixed with spherical glands, older branches without leaves at the base, bark peeling off with age; nodes not thickened, internodes 1.5–3 mm long, covered with setose trichomes mixed with spherical glands, not winged. Leaves ascending, imbricate, not amplexicaul; petiole 0.4–0.6 mm long, flat, covered with setose trichomes mixed with spherical glands; blade 3.5–8 × 1–2.5 mm, chartaceous, discolorous (when dry), adaxial surfaces brown, abaxial surface green, narrowly elliptic, apex acuminate, short-setose or not, trichomes 0.08–1 mm long, base attenuate, margin entire, setose-ciliate, adaxial surface sparsely covered with setose trichomes, abaxial moderately covered with setose trichomes, both surfaces densely covered with spherical glands, 1 - veined, visible on both surfaces, secondary and tertiary veins absent. Inflorescence reduced to one bracteate flower, lateral or at the apices of the branches, bracts ca 2 × 0.8 mm, narrowly elliptic. Flowers 5 - merous; pedicel 0.5–0.7 mm long, brownish, covered with setose trichomes mixed with spherical glands; hypanthium 1.7–2.7 × 1–1.5 mm, campanulate, cream (when dry), 10 - costate, densely covered with spherical glands; calyx tube ca 0.2 mm long; sepals 1–2 × 0.1–0.2 mm, smaller than the hypanthium, cream (when dry), not foliaceous, chartaceous, subulate, apex rounded, not veined, covered with spherical glands, trichomes between the sepals absent; petals 5–5.2 × 2.3–3.5 mm, yellow, oblong, apex acuminate, margin glabrous; androecium dimorphic, concolorous, yellow, stamens 10, anthers polysporangiate; larger (antesepalous) stamens 5, filaments ca 2.5 mm long, anthers 1.3–1.4 mm long including beak, oblong, beak ca 0.1 mm long, pedoconnective 1.2–1.6 mm long, ventral appendage 0.5–0.6 mm long, apex bilobed; smaller (antepetalous) stamens 5, filaments 2.3–2.5 mm long, anthers 1.3–1.4 mm long including beak, oblong, beak ca 0.1 mm long, pedoconnective 0.8–1 mm long, ventral appendage ca 0.3 mm long, apex truncate; ovary ca 1 × 1 mm, 3 - locular, globose, superior, glabrous; style ca 5 mm long, yellow, slightly curved at the apex, stigma punctiform. Capsules 2–2.3 × ca 1.5 mm, oblong, smooth, brown blackish (when dry), sepals persistent on the immature fruits, hypanthium covering the entire capsule and peeling off as the fruit matures, dehiscence basipetal, columella deciduous. Seeds not seen.
Distribution and habitat
Microlicia xanthopetala was found in Morro da Tesoura, Mucugê, Bahia, Brazil, where it probably occurs in campo rupestre (Fig. 3).
Phenology
Collected with flowers and fruits in August.
Etymology
The specific epithet xanthopetala is derived from the Greek words xanthos (Ξάνθος = yellow) and pétălon (πέταλον = petals) (Stearn 1983), in reference to the yellow petals in this species.
Preliminary IUCN conservation assessment
Like the previous species, we only know M. xanthopetala from a single collection. The lack of data prevents a proper threat assessment of this species, so we also preliminarily assess M. xanthopetala as Data Deficient (DD) based on the IUCN Red List categories and criteria (IUCN 2022).
Notes
Microlicia xanthopetala was previously identified as Microlicia aurea Wurdack probably because both species have petiolate leaves, discolorous (when dry) and 1 - veined leaf blades, flowers with yellow petals and stamens, and polysporangiate anthers (Wurdack 1983). The differences between them are mentioned in the diagnosis. Microlicia aurea is found only in Rio de Contas, Bahia, Brazil (Wurdack 1983; SpeciesLink network 2024).
Microlicia xanthopetala also bears some resemblance to Microlicia ganevii Woodgyer & R. Romero. Both species are from Bahia and share petiolate leaves, discolorous leaf blades (when dry), and flowers with yellow petals and androecium, and stamens with polysporangiate anthers (Wurdack 1983; Romero and Woodgyer 2018). Microlicia ganevii has branches, leaves, and hypanthium covered with glandular trichomes mixed with spherical glands (vs setose trichomes and spherical glands in M. xanthopetala), 3–5 - veined leaf blades (vs 1 - veined), and narrowly triangular sepals (vs linear) (Romero and Woodgyer 2018). Until now, M. ganevii is found only in Catolés (Romero and Woodgyer 2018).
Checklist of species of Microlicia with yellow corollas in Bahia
In the state of Bahia, there are 82 taxa of Microlicia (Fidanza et al. 2024; Pacifico and Fidanza 2024; Romero et al. 2024; Versiane 2024). Of these, 22 species have yellow corollas, a relatively uncommon characteristic in the genus, where corollas with magenta or variations of this colour predominate. Here, we add three new species with yellow corollas to the state’s flora: Microlicia aequalis, M. eimeariana, and M. xanthopetala. Bahia is the state with the highest number of Microlicia with yellow corollas (Table 1).
description: Published as part of Romero, Rosana, Pataro, Luciano & Versiane, Ana Flavia A., 2025, Three new species of Microlicia (Melastomataceae) with yellow corollas from Chapada Diamantina, Bahia, Brazil, pp. 157-167 in Plant Ecology and Evolution 158 (2) on pages 157-167, DOI: 10.5091/plecevo.140649