Microlicia integra R. B. Pacifico, Almeda & R. Goldenb., 2025

Pacifico, Ricardo, Almeda, Frank, Engels, Mathias Erich & Goldenberg, Renato, 2025, Two new species of Microlicia (Melastomataceae) from unprotected campo rupestre in the western Chapada Diamantina, Bahia, Brazil, PhytoKeys 266, pp. 253-265 : 253-265

Microlicia integra R. B. Pacifico, Almeda & R. Goldenb. sp. nov.

Figs 1 , 2 B, C

Type.

Brazil • Bahia: Ibitiara. Serra de Ibitiara, Chapada Diamantina , 12°35'50"S, 42°05'34.7"W, 1,218 m, 19 December 2024, fl. fr., R. Pacifico 736 & I. V. Castro ( holotype: UPCB barcode UPCB 0095366 !, isotypes: CAS!, HUEFS!, RB!, SPF!) .

Diagnosis.

Differs from M. minima Markgr. by the petiolate leaves (vs. sessile in M. minima ), each calyx lobe alternating with an eglandular trichome 0.7–1 mm long (vs. these trichomes absent), petals entirely pink (vs. magenta with a cream base) that are 7–11 mm long (vs. 4.5–6 mm long), and dimorphic stamens (vs. isomorphic to subisomorphic).

Description.

Copiously branched erect shrubs 0.3–1.3 m tall. Branchlets light green (when fresh), quadrangular, glandular-punctate, the stem angles with inconspicuous narrow wings ca. 0.1 mm wide. Leaves ascending (when fresh), flat, decussate, ca. 2 times longer than the internodes, on short flattened petioles 0.2–0.6 mm long; blades 1.8–3.9 (– 4.5) × 0.7–1.2 (– 1.6) mm, narrowly elliptic, papyraceous, both surfaces vivid green when fresh, pale green when dry, base cuneate to attenuate, margin entire, the apex acute to obtuse, 1 - nerved from the base, venation slightly impressed on the abaxial surface and inconspicuous on the adaxial surface, both surfaces densely glandular-punctate. Flowers 5 - merous on inconspicuous pedicels 0.3–0.4 mm long, solitary, terminal, not clustered at the apex of the branchlets. Hypanthia (at anthesis) 2.4–2.7 mm long, 2.5–3 mm wide at the torus, yellowish green when fresh, turning brown when dry, campanulate, densely glandular-punctate. Calyx tubes 0.1–0.3 mm long; calyx lobes (at anthesis) 1.6–2.0 mm long (excluding apical trichome), 0.9–1.3 mm wide at the base, triangular, apex acute terminating in an eglandular trichome ca. 0.4–0.5 mm long (tardily deciduous), externally glandular-punctate, the margin entire and glabrous, each calyx lobe alternating with an eglandular trichome ca. 0.7–1 mm long (tardily deciduous). Petals 7–11 × 5–7 mm, widely obovate, pink, margin entire, apex rounded to bluntly acute, both surfaces glabrous. Stamens 10, dimorphic; larger (antesepalous) stamens 5, filaments 3.6–4.3 mm long, yellow, pedoconnectives 6.1–6.9 mm long, yellow, appendages 1.3–1.6 mm long, yellow, apex truncate to slightly emarginate, thecae 1.9–2.1 mm long (excluding rostra), oblong, yellow, externally corrugated (polysporangiate), rostra 0.4–0.5 mm long, white, the circular pores 0.2–0.3 mm wide, ventrally inclined; smaller (antepetalous) stamens 5, filaments 3.2–3.8 mm long, yellow, pedoconnectives 2.9–3.3 mm long, yellow, appendages 0.9–1.1 mm long, apex truncate, thecae 1.3–1.6 mm long (excluding rostra), oblong, yellow becoming brownish in post-anthesis, externally corrugated (polysporangiate), rostra 0.3–0.5 mm long, the circular pores 0.1–0.2 mm wide, ventrally inclined. Ovaries ca. 1.6 × 1.3 mm, subglobose, superior, glabrous, 3 - locular; styles 7.1–8.5 mm long, linear, pink with a yellow base, stigma punctiform. Loculicidal capsules 2.7–2.9 × 2.3–2.7 mm (immature), ovoid, brownish when dry, initially enveloped by the ± constricted hypanthium at the apex, then tardily rupturing and flaking away with age, the apex not exceeding the torus, dehiscent from the apex to the base, columellas caducous. Seeds not seen.

Distribution, habitat, and phenology.

Known only from the Serra de Ibitiara (western Bahia; Fig. 3 ), where it has been collected on campo rupestre between 1,096 and 1,218 m elevation (Fig. 2 A ), growing on white sand. Collected flowering and fruiting in September and November.

Recognition.

Overall, M. integra can be recognized by its branches and leaves that are glandular-punctate, 1 - nerved, and petiolate; reduced blades 1.8–3.9 (– 4.5) mm long; triangular calyx lobes, each alternating with an eglandular trichome 0.7–1 mm long (tardily deciduous); petals entirely pink, and dimorphic stamens that are entirely yellow.

Besides M. minima (as detailed in the diagnosis), M. integra is also morphologically similar to M. pinheiroi . The new species differs by its modally shorter petioles, 0.2–0.6 mm long (vs. 0.6–1 mm long in M. pinheiroi ); leaf blades 1.8–3.9 (– 4.5) mm long (vs. 4–6 mm long); shorter calyx lobes, 1.6–2.0 mm long (vs. 2.4–2.7 mm long); each calyx lobe alternating with an eglandular trichome ca. 0.7–1 mm long (vs. these trichomes absent); and petals entirely pink (vs. magenta with a cream base). Another possible relative is M. flavistyla , from which M. integra differs by the leaves and calyx lobes eciliate (vs. ciliate with eglandular trichomes), modally narrower leaves 0.8–1.2 (– 1.6) mm wide (vs. 1.2–3.3 mm wide), each calyx lobe alternating with a deciduous eglandular trichome (vs. these trichomes absent), and fruiting hypanthia not forming a constricted neck above the capsule summit (vs. neck ca. 0.6 mm long). Microlicia integra is clearly allopatric with both M. minima and M. pinheiroi , with a significant gap between their distributions (Fig. 3 ). It also appears to be parapatric with M. flavistyla , although these species grow in different parts of the same mountain range that crosses the municipality of Ibitiara.

Etymology.

The specific epithet integra comes from the Latin integer (“ entire, complete ”), referring to the fact that this species bears petals that are entirely pink. In contrast, in its closest relative, M. minima , the petals have a cream base.

Additional specimens examined ( paratypes).

Brazil • Bahia: Ibitiara. Cadeia do Espinhaço, Chapada Diamantina , 12°35'18"S, 42°05'32"W, 1,200 m, 6 September 2022, fl., fr., M. E. Engels 9981 & D. Liebsch ( UPCB!) ; • Serra de Ibitiara, Chapada Diamantina , 12°35'32"S, 42°05'30.8"W, 1,201 m, 19 December 2024, fl. fr., R. Pacifico 737 & I. V. Castro ( CAS!, RB!, UPCB!) ; • Serra de Ibitiara, Chapada Diamantina , 12°35'17.9"S, 42°05'31.5"W, 1,196 m, 19 December 2024, fl. fr., R. Pacifico 738 & I. V. Castro ( CAS!, RB!, UPCB!) .

Figures

Figure 1. Microlicia integra. A. Habit; B. Leaf adaxial (left) and abaxial (right) surfaces; C. Branchlet terminating in a flower at anthesis; D. Apical branch terminating in a floral bud; E. Flowering hypanthium and calyx lobes; F. Petal in adaxial view; G. Flower in lateral view; H. Antepetalous (left) and antesepalous (right) stamens; I. Gynoecium; J. Branchlet terminating in a capsule enveloped by the hypanthium. Drawn from R. Pacifico 736 & I. V. Castro.

Figure 2. A. Landscape at the Serra de Ibitiara, Bahia, Brazil; B, C. Microlicia integra; B. Habit; C. Flowering branches; D – F. Microlicia flavistyla; D. Habit; E. Branchlet terminating in a flower at anthesis, view from behind; F. Branchlet terminating in a flower at anthesis, in lateral view; Photos: A – C, by R. Pacifico; D – F, by M. E. Engels.

Figure 3. Distribution of Microlicia integra and probable relatives. A. Brazil with Bahia state highlighted; B. Bahia; C. Distribution of M. integra, M. minima, and M. pinheiroi on the Chapada Diamantina and surroundings.