Microlicia aequalis R. Romero & Versiane 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 aequalis

description: 1.Microlicia aequalisR. Romero & Versiane sp. nov.
Fig. 2, Supplementary material 1
Type
BRAZIL – Bahia • Abaíra, [Distrito de Catolés], Serra das Brenhas; 13°19’S, 41°53’W; 1890 m; 21 Oct. 1992; fl., fr.; W. Ganev 1291; holotype: HUEFS!; isotypes: HUFU! [HUFU 00075914], K! [01899807], SPF! [SPF 0008697], US!.
Diagnosis
Microlicia aequalis is morphologically similar to Microlicia morii. However, it can be easily distinguished by the leaf blade covered with setose trichomes mixed with glandular trichomes on both surfaces (vs only spherical glands in M. morii) and crenulate margin (vs entire margin).
Description
Shrubs, erect, branched, ca 1.3 m tall. Younger and older branches terete, brownish, covered with setose trichomes mixed with spherical glands, older branches without leaves at the base, bark peeling off with age; nodes not thickened, internodes 1–2.5 mm long, covered with setose trichomes mixed with spherical glands, not winged. Leaves horizontal, not imbricate, not amplexicaul; petiole 0.8–1 mm long, flat, covered with setose trichomes; blade 5–8.6 × 3–5 mm, chartaceous, discolorous (when dry), adaxial surface dark green to brownish, abaxial surface light green, elliptic to widely elliptic, apex acuminate, not setose, base rounded, margin crenulate, setose-ciliate at the bases, both surfaces covered with setose trichomes mixed with glandular trichomes, the setose trichomes concentrated mainly on the nerves, sometimes covering only 1 / 3 of the blade, 1–3 - veined, visible on both surfaces, tertiary veins absent. Inflorescence reduced to one bracteate flower, lateral or at the apices of the branches, bracts 2–3 × 1–2 mm, elliptic. Flowers 5 - merous; pedicel 0.9–1.3 mm long, brownish, covered with setose trichomes mixed with spherical glands; hypanthium ca 3 × 2.5–3 mm, campanulate, brownish (when dry), covered with spherical glands, setose trichomes only at the base, slightly 10 - costate; calyx tube ca 0.1 mm long; sepals 1.5–2.3 × 0.6–1 mm, smaller than the hypanthium length, greenish to brownish (when dry), not foliaceous, chartaceous, narrowly triangular, apex acute-setose, trichomes 0.1–0.2 mm long, not veined, covered with spherical glands, trichomes between the sepals absent; petals 4.8–6 × 3.4–4.5 mm, yellow, oblong, apex acuminate, margin glabrous; androecium isomorphic, concolorous, yellow, stamens 10, isomorphic, anthers polysporangiate, concolorous; filaments 2.2–2.5 mm long, anthers 2.2–2.3 mm long including beak, ovate, beak ca 0.2–0.3 mm long, pedoconnective 0.6–0.8 mm long, ventral appendage absent; ovary ca 2 × 1.5 mm, 3 - locular, globose, superior, glabrous; style ca 5.5 mm long, yellow, straight, stigmas punctiform. Capsules ca 2.5 × 2.3 mm, oblong-campanulate, smooth, brownish (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 aequalis was found in Serra das Brenhas, Catolés district, Abaíra municipality, Bahia, Brazil (Fig. 3). According to the exsiccata label, it occurs in campo rupestre with sandy-gravelly soil and many outcropping rocks.
Phenology
Collected with flowers and fruits in October.
Etymology
The specific epithet aequalis is derived from the Latin adjective aequalis (“ equal ”) (Stearn 1983), in reference to the isomorphic androecium in this species.
Preliminary IUCN conservation assessment
The species is only known from a single collection made 32 years ago. In 2022, we attempted to locate individuals of this species but were unsuccessful. Due to the lack of data, it is difficult to assess whether the species is extinct. Therefore, we preliminarily assess M. aequalis as Data Deficient (DD) following the IUCN Red List categories and criteria (IUCN 2022).
Notes
Microlicia aequalis is similar to Microlicia morii Wurdack, Microlicia oligochaeta Wurdack, and Microlicia glazioviana Cogn. These four species have petiolate leaves and discolorous, 3 - veined leaf blades. Like M. aequalis, M. morii and M. oligochaeta occur in the Chapada Diamantina, Bahia, while M. glazioviana is endemic to the Iron Quadrangle in Minas Gerais. Microlicia aequalis and M. oligochaeta have branches and leaves covered with setose trichomes mixed with glandular trichomes. However, M. oligochaeta differs in having flowers with pink petals (vs yellow in M. aequalis), a dimorphic and bicolorous androecium (vs isomorphic, concolorous), and polysporangiate anthers (vs tetrasporangiate) (Wurdack 1983). Microlicia aequalis and M. glazioviana have branches covered with setose trichomes mixed with spherical glands, crenulate leaf blades at the margin, and tetrasporangiate anthers. However, M. glazioviana differs in having the hypanthium densely covered with setose trichomes mixed with spherical glands (vs spherical glands and sparse setose trichomes only at the base in M. aequalis), pink petals (vs yellow), dimorphic and bicolorous androecium (vs isomorphic, concolorous) (Cogniaux 1888). Microlicia aequalis and M. morii share several characteristics, including yellow-petaled flowers, an isomorphic androecium, and a pedoconnective without a ventral appendage. The distinguishing features between M. aequalis and M. morii are mentioned in the diagnosis.
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