Microlicia nortecipoana R.B. Pacifico, Fidanza & Almeda, 2017

Pacifico, Ricardo B., Fidanza, Karina & Almeda, Frank, 2017, Two new species of Microlicia (Melastomataceae) from the Rupestrian Grasslands of Serra do Cipó, Minas Gerais, Brazil, Phytotaxa 316 (1), pp. 39-50 : 40-44

Microlicia nortecipoana R.B. Pacifico, Fidanza & Almeda , sp. nov. ( Fig. 1–2 ; Fig. 3. A, G )

Diagnosis:— Microlicia nortecipoana can be recognized by its 1-nerved lanceolate leaves with a rounded base, the margin bearing long simple hairs (1.5–2 mm long) and densely covered with spherical sessile glands born on the punctations of both faces, 5-merous flowers with the hypanthium densely covered with long simple hairs (1.5–2 mm long) mixed with sessile glands, linear calyx lobes, pink petals with an acuminate apex terminating in an apical seta, and bicolored tetrasporangiate anthers.

Type:— BRAZIL. Minas Gerais: Congonhas do Norte, Retiro do Barbado, morro a esquerda do rio Preto, 43º46’W, 18º52’S, 22 April 1982, M. C. E. Amaral, A. Furlan & N. Hensold CFSC 8391 (Holotype: SPF!, Isotypes HUEM!, SP!).

Erect shrub, ca. 25 cm, mostly dichotomously branched. Branchlets green, subquadrangular, yellow-translucent glandular-punctate (when fresh) intermixed with simple hairs 1.5–2 mm long, older branches brownish, becoming terete and glabrescent towards the base. Leaves decussate and ascendant, subsessile, slightly longer than the internodes, concentrated distally on the branches; blade 3–6 × 1–2 mm, green and concolorous (when fresh), becoming light brown and discolorous when dried (the adaxial surface becoming darker), lanceolate, base rounded, apex acuminate, terminating in a hair ca. 1.5 mm long, margin slightly crenulate and ciliate with simple hairs 1.5–2 mm long, simple hairs white flushed with pink and elongate when fresh (becoming twisted when dried), 1-nerved, the midvein white, stout, enlarged at the base and slightly prominent on the abaxial surface, leaf surfaces densely covered (when fresh) with yellow-translucent spherical glandular-punctations on both faces. Flowers 5-merous, solitary, ebracteolate, concentrated at the branchlets’ apex; pedicels 0.9–1.0 mm long; hypanthium 2.0–2.1 × 2.0– 2.2 mm, campanulate, glandular-punctate and densely covered with simple hairs 1.5–2 mm long; calyx lobes 2.1–2.9 × 0.2–0.4 mm, linearsubulate, apex acuminate, apical seta 0.9–1.4 mm long, margin entire and ciliate with simple hairs 1.5–2 mm long, indumentum similar to the hypanthium; petals 6.3–6.6 × 3.2–3.7 mm, pink, obovate, apex acuminate, terminating in a hair 0.5–1.5 mm long, margin entire, glabrous; stamens 10, dimorphic, the longer (antesepalous) ones with filaments 3.2–3.4 mm long, pink, connective prolonged 3.5–3.7 mm long below the thecae, pink, appendage 1.2–1.3 mm long, yellow, dorso-ventrally flattened, apex rounded, thecae 1.2–1.3 mm long, purple, oblong, surface smooth, tetrasporangiate, rostrum 0.3–0.4 mm long, the pore widely circular, the shorter (antepetalous) ones with filaments 3.2–3.8 mm long, pink, connective prolonged 0.9–1.0 mm long below the thecae, yellow, appendage 0.1–0.2 mm long, yellow, apex truncate, thecae 1.3–1.4 mm long, yellow, oblong, surface smooth, tetrasporangiate, rostrum 0.3–0.4 mm long, the pore widely circular; ovary 1.9–2 × 1.6–1.9 mm, globose, glabrous, superior, 3-locular; style 3.2–3.6 mm long, purple, linear, glabrous, stigma punctiform. Capsules not seen.

Distribution and phenology:—This species is found only in northwestern Serra do Cipó ( Fig. 7 ), in the Preto river valley ( Fig. 4 A ), where it is probably endemic. It was collected at 1,285 m elevation on white and quartzitic rocky outcrops along river slopes. Collected with flowers in April.

Etymology:—the specific epithet emphasizes the northern Serra do Cipó where this species is probably endemic. Since the Preto river valley is not included in any Brazilian governmental protected area, we hope that the recognition of M. nortecipoana will spotlight the importance of this area and promote conservation efforts in the region.

Additional specimens examined (paratypes):— BRAZIL. Minas Gerais: Congonhas do Norte, vale do Rio Preto , campo rupestre, 18°50’59.0”S, 43°44’54.8”W, 1,285 m, 2 September 2016, R. Pacifico 207a, C. A. Rossi & D. L. Estevam ( HUEM!) ; vale do Rio Preto , campo rupestre, 18°50’59.0”S, 43°44’54.8”W, 1,285 m, 2 September 2016, R. Pacifico 207b, C. A. Rossi & D. L. Estevam ( HUEM!) .

Conservation status:—The small population of M. nortecipoana is known from only one locality in the Preto river valley on the Serra do Cipó. The three collections that were available for study all have geographic coordinates. The extent of occurrence (EOO) is 0 km² and the area of occupancy (AOO) is 8 km ². Because M. nortecipoana has a limited AOO, does not occur in a protected area, and its campo rupestre habitat is subjected to periodic fires and mining activity, we recommend a classification of Critically Endangered [CR B2ac(iv)].

Affinities:— Microlicia nortecipoana is most similar to Microlicia petiolulata Cogn. ex R.Romero & Woodgyer (2010: 69) . Both species have leaves that are similar in size (3–6 mm long, M. nortecipoana ; 3–7 mm long, M. petiolulata ) and discolorous when dried, an indumentum of simple hairs intermixed with glandular-punctations covering young branches and hypanthia, linear calyx lobes, pink petals, and bicolored anthers. Microlicia nortecipoana differs in having leaves without an evident petiole, the base rounded, both surfaces that are glandular-punctate, and the margin with longer hairs. These two species occur only in central Minas Gerais, but not sympatrically. Microlicia petiolulata can be distinguished by its petiolate leaves, cordate base, indumentum of simple hairs on both faces with shorter simple hairs on the margin. It is known only from the region around Diamantina, Minas Gerais.

Microlicia insignis Chamisso (1834: 388) is probably the species with leaves that most closely resemble those of M. nortecipoana , considering that its leaf blades are lanceolate to oval-lanceolate, with long simple hairs often restricted to the margins ( Fig. 3. M ). However, the flowers of M. insignis have a distinctive androecium—the appendages of the antesepalous stamens are bilobate at the apex (vs. rounded in M. nortecipoana ), while those of the antepetalous stamens are up to 0.5 mm long (vs. 0.1–0.2 mm long in M. nortecipoana ), with all thecae completely yellow ( Fig. 3. L ), and polysporangiate anthers with a longer rostrum (0.5 mm long; vs. 0.3–0.4 mm long in M. nortecipoana ). Besides, the hypanthium of M. insignis has an indumentum that is much sparser than that of M. nortecipoana , and its calyx lobes are triangular-lanceolate. Recent studies report Microlicia insignis from Serra dos Pireneus ( Versiane et al. 2016) and Serra Dourada ( Machado 2015), both in the state of Goiás, and from Jalapão in Tocantins state (Guilherme Antar, unpublished data). Additional specimens of M. insignis have been collected at Barra dos Garças in Mato Grosso state ( Lima 58-3037, RB), Serra do Cachimbo in Pará state (e.g., Prance et al. 25234, RB), and photos of this species were taken in Chapada Imperial in the Distrito Federal ( Fig. 3. L–M ) [morphological features of M. insignis were obtained from Machado (2015) and Versiane et al. (2016)].

Several species of Microlicia that occur on Serra do Cipó have ovate leaves, an indumentum of simple hairs mixed with apparently sessile glands, pink petals and bicolored anthers including Microlicia cordata Chamisso (1834: 390) , Microlicia hirticalyx R. Romero & Woodgyer (2011: 163) ( Fig. 3. E, J ), Microlicia fasciculata Martius ex Naudin (1845: 180) ( Fig. 3. F, K ), Microlicia hirto-ferruginea Naudin (1845: 176) ( Fig. 3. D, I ), Microlicia serrulata Chamisso (1834: 390) ( Fig. 3. C, H ), and Microlicia stricta Cogniaux (1883: 93) ( Fig. 3. B ). Of these species, the only one that also has leaves with simple hairs restricted to the margin is M. serrulata , but this latter species is readily recognized by its wider leaves, with a much sparser indumentum consisting of smaller simple hairs (up to 0.8 mm long), and by its triangular calyx lobes. Microlicia stricta has ciliate leaf margins but it also has sparse simple hairs on the abaxial surface, triangular calyx lobes, and its hypanthia become cream-colored when dried, more closely resembling Microlicia graveolens De Candolle (1828: 119) and M. fasciculata than M. nortecipoana .

Figures

FIGURE 1. Microlicia nortecipoana. A. Habit. B. Detail of the leaf blade (abaxial view). C. Floral bud. D. Petal (adaxial view). E. Antepetalous (left) and antesepalous (right) stamens. F. Gynoecium. (A and C–F from M.C.E Amaral et al. CFSC 8391; B from R. Pacifico et al. 207a).

FIGURE 2. Microlicia nortecipoana.A. Habit of a living specimen. B. Detail of a sterile branch.C. Detail of the leaves. D. Flower (lateral view). (A–C from R. Pacifico et al. 207a; D from M.C.E Amaral et al. CFSC 8391).

FIGURE 3. A–K. Abaxial leaf surfaces and floral buds of M. nortecipoana and some of its probable relatives. A, G. M. nortecipoana (M.C.E. Amaral et al. CFSC 8391). B. M. stricta (M. Barreto 9948). C, H. M. serrulata (J. Lovo et al. 34). D, I. M. hirto-ferruginea (R. Pacifico 137 & A. Carmo). E, J. M. hirticalyx (R. Pacifico 165 & A. Carmo). F, K. M. fasciculata (R. Pacifico 164 & A. Carmo). L–M. Microlicia insignis, pictures of a living specimen. L. Detail of a flower. M. Detail of a vegetative branch. (L–M by João Medeiros). Scale bars: 2 mm.

FIGURE 4. A. Landscape of Preto River Valley, Congonhas do Norte, Minas Gerais, the type locality of Microlicia nortecipoana. B. Landscape of southwestern Serra do Cipó, near highway MG-010, Minas Gerais, the type locality of Microlicia obovatifolia. (All by C.A. Rossi).

FIGURE 7. Southeastern Brazil. Geographic distribution of Microlicia nortecipoana and Microlicia obovatifolia in Minas Gerais state, at elevations above 1,000 m.