Microlicia urceolata J. Coelho & R. Romero, 2018

Jesus, Jôane Coelho De, Romero, Rosana & Roque, Nádia, 2018, Two new species of Microlicia (Melastomataceae) from the Septentrional Espinhaço, Bahia, Brazil, Phytotaxa 343 (3), pp. 240-248 : 244-247

Microlicia urceolata J. Coelho & R. Romero , sp. nov.

Type:— BRAZIL. Bahia: Licínio de Almeida, Riacho de areia, campo rupestre, 1163 m alt., 14º45’32,5”S, 42º34’38,3”W, 27 May 2014, fl. fr., Coelho, Alves, Borges & Stadnik 17 (holotype: ALCB!; isotypes: HUEFS!, HUFU!, NY!, RB!, UPCB!). ( Figures 4–5 )

Diagnosis:— The new species presents the prominent urceolate fruit with a conspicuous constriction in the medium portion below the torus, forming a tubular neck on the mature fruit, an uncommon feature in Microlicia . Microlicia urceolata resembles M. mucugensis but differs by the tetrasporangiate anthers (vs. polysporangiate anthers), 3-locular ovary (vs. 5-locular) and hypanthium terete to urceolate, constricted (vs. hypanthium oblong without a constriction).

Erect shrub, ca. 0.5 m tall, much branched. Young branches quadrangular, slightly 4-winged, indumentum dense, a mixture of spherical, golden glands and short-stalked, golden, gland-tipped trichomes 0.1–0.2 mm long, older branches terete, glabrescent, leaf scars conspicuous; internodes 1.5–5 mm long. Leaves decussate, sessile, discolorous, adaxial surface dark green, abaxial surface pale green (assessed when dry); leaf blade lk, 7–12 × 3.5–7 mm, apex acute or obtuse, base rounded, margin entire, indumentum on both surfaces dense, a mixture of impressed, spherical, golden glands and short-stalked, golden, gland-tipped trichomes 0.1–0.2 mm long, slightly, glutinous, 3 nerved from the base, central vein thickened and prominent on abaxial surface, impressed on adaxial surface. Flowers solitary, lateral or terminal, 5-merous, zygomorphic; pedicel short, ca. 0.8 mm long, covered by spherical, golden glands and short-stalked golden, gland-tipped trichomes 0.1–0.2 mm long; hypanthium terete to urceolate, with a constriction in its medium portion forming a tubular neck on the mature fruit, 5–6.1 × 3.6–3.9 mm, densely covered with short-stalked, golden, gland-tipped trichomes 0.1–0.2 mm long, glutinous; sepals narrowly triangular, ca. 4 × 1.4 mm, green to vinaceous at apex (in fresh material), apex acute with an apical seta, ca. 0.5 mm long, margin entire, covered with short-stalked, golden, gland-tipped trichomes 0.1–0.2 mm long, glutinous; petals magenta, obovate, 9.5–12.5 × 6.2–7.2 mm, apex asymmetrical, acuminate, base cuneate, margin entire, slightly involute in the apex; stamens 10, dimorphic, antesepalous 5, filaments magenta, ca. 5 mm long, pedoconnective lilac becoming magenta, ca. 3 mm long, ventral appendage yellow, ca. 1.6 mm long, rounded, anthers yellow becoming magenta, oblong, ca. 3.4 mm long (including rostrum), tetrasporangiate, rostrum yellow, ca. 0.8 mm long, pore ventrally curved, antepetalous 5, filaments magenta, 4–4.5 mm long, pedoconnective yellow, ca. 1.2 mm long, ventral appendage yellow, ca. 0.9 mm long, rounded, anthers yellow, oblong, 3–3.4 mm long (including rostrum), tetrasporangiate, rostrum yellow, 0.6–0.8 mm long, straight or horizontal, pore inclined ventrally; ovary globose, 3–4 × 2.4–3.7 mm, superior, 3-locular, glabrous; style magenta, straight or flexuous, ca. 7 mm long, stigma magenta, punctiform, papillose. Capsule globose to ovoid, 3.6 ‒ 4.3 × 3.5 ‒ 4.2 mm, dehiscing into 3 valves from the apex, with a conspicuous urceolate hypanthium recovering the capsule and peeling off with the age; seed oblong, slightly curved, 0.4–0.6 mm long, testa foveolate.

Additional specimens examined:— BRAZIL, BAHIA, Licínio de Almeida, Serra Geral, Riacho de Areia , 1163 m alt., 14º45’32,5”S, 42º34’38,3”W, 12 May 2015, fl. fr., J. Coelho et al. 49 (ALCB, HUEFS) ; idem, 31 May 2016, fl. fr., J. Coelho et al. 110 (ALCB, CEPEC) ; idem, 21 March 2017, fl. fr., J. Coelho et al. 170 (K, RB) .

Distribution, habitat and conservation status:— Microlicia urceolata was found so far only in Serra Geral, Licínio de Almeida municipality, in the state of Bahia, Brazil ( Figure 3 ). The individuals were collected only in vegetation on rocky fields (campo rupestre) at the “Riacho de Areia” locality. This species occupies an area near the roadside that is being degraded in recent years due to the frequent enlargement of the road after the periods of rainfall. Based on georeferenced data from cited collections, the area of occupancy was calculated using GeoCAT ( Bachman et al. 2011). Due to the restricted extent of occurrence and area of occupancy (AOO= 4 km 2), M. urceolata should be considered CR B1ab (iii) + 2ab (iii) according to IUCN categories and criteria (2001, 2014), with attention to a critically endangered category (CR).

Etymology:— The specific epithet refers to the conspicuous constriction in the hypanthium, a feature uncommon in Microlicia species.

Discussion:— The prominent urceolate fruit with a conspicuous constriction in the medium portion below the torus, forming a tubular neck on the mature fruit ( Figures 4H , 5E ) and the presence of straight and horizontal rostrum in the anthers of the antepetalous stamens ( Figures 4 E, F ) are remarkable features that distinguish this species from its congeners. The new species resembles Microlicia mucugensis (Wurdack 1988: 294) Almeda & Martins (2001: 4) by having branches with interwoven of spherical, golden glands and short-stalked, golden, gland-tipped trichomes 0.1– 0.2 mm long, sessile and glutinous leaves, narrowly triangular sepals and magenta petals. However, M. mucugensis differs by having orbicular or elliptic leaves, oblong hypanthium without any constriction, polysporangiate anthers, and 5-locular ovary.

The formula for M. urceolata in the multi-access key for the species of Microlicia in Bahia ( Woodgyer 2005) is BDHKOQUVai.

Figures

FIGURE 3. Map of the municipality of Licínio de Almeida, Espinhaço Range, and pictures taken from rocky caatinga and rocky field (Photographs: L. Campos).

FIGURE 4. A–I: Microlicia urceolata. A. Flowering branch. B. Hypanthium and sepals. C. Flower. D. Petal. E.Antepetalous stamen with pore ventrally curved. F. Antepetalous stemen with apical pore. G. Antesepalous stamen. H. Fruit. I. Gynoecium (drawn from J. Coelho 49).

FIGURE 5. Microlicia urceolata A–E: A. Habit. B. Flowering branch. C. Floral bud. D. Flower. E. Fruit. (Photographs: J. Coelho).