Microlicia trembleyiformis Naudin, Ann. Sci. Nat., Bot. Ser . 3, 3: 172. 1845.

Pacifico, Ricardo, Almeda, Frank, Penneys, Darin S. & Fidanza, Karina, 2022, Systematics of the Trembleya sensu stricto clade of Microlicia (Melastomataceae, Lavoisiereae), PhytoKeys 216, pp. 1-101 : 1

10. Microlicia trembleyiformis Naudin, Ann. Sci. Nat., Bot. Ser. 3, 3: 172. 1845.

Fig. 29

Type.

Brazil. "Minas Geraes, in campis circa urbem Villa Ricca frequens" [Minas Gerais, Ouro Preto], 1816-1821, [catal. B1, n° 160] A. Saint-Hilaire s.n. (lectotype, first-step designated by Martin and Cremers (2007), second-step designated here: P [P002297746]!; isolectotype: F [F0360366]!; image of lectotype is available at http://coldb.mnhn.fr/catalognumber/mnhn/p/p02297746) .

Description.

Erect shrubs 0.5-1.0 m tall. Branchlets quadrangular, glandular-punctate and sparsely covered with eglandular trichomes 0.1-0.5, light green (when fresh). Internodes 0.2-1.1 cm long, angles with narrow wings ca. 0.2 mm wide. Petioles 0.3-1.4 mm long. Leaf blades 4-25 mm long, 1.5-12 mm wide, papyraceous (when dry), ovate or elliptic, both surfaces green (when fresh), adaxial surface blackened and abaxial surface pale green to pale brown (when dry), discoloured (when dry), base rounded or attenuate, apex acute or obtuse, margin flat, slighly serrulate and ciliate with eglandular trichomes 0.1-0.4 mm long, 5-nerved from the base, one pair of acrodromous veins and one pair of tenuous veins close to the margin, tertiaries evident on the abaxial surface, nearly perpendicular to the mid-vein, little reticulate and branching apically, adaxial surface glandular-punctate, abaxial surface densely glandular-punctate and sparsely covered with eglandular trichomes 0.1-0.5 mm long around the veins. Inflorescences reduced to solitary flowers on the aplical region of the branches. Bracts absent. Bracteoles (at anthesis) with petioles 0.3-0.5 mm long, blades 2.4-6.1 mm long, 1.0-3.2 mm wide, ovate or elliptic, base cuneate, apex acute to obtuse, margin slightly serrulate and ciliate with eglandular trichomes 0.1-0.4 mm long, 3-nerved, indumentum like that of the principal leaves. Flowers 5-merous, pedicels (at anthesis) 0.7-1.9 mm long. Hypanthia (at anthesis) 2.2-2.6 mm long, 1.8-2.2 mm wide at the torus, campanulate to urceolate, light green (when fresh), externally glandular-punctate and sparsely covered with eglandular trichomes 0.1-0.5. Calyx tubes 0.2-0.4 mm long. Calyx lobes (at anthesis) 1.5-2.1 mm long, 0.5-0.7 mm wide at the base, narrowly triangular, apex acute, margin entire, (when fresh) light green, externally like the hypanthia. Petals 6.1-7.9 mm long, 3.0-3.5 mm wide, magenta, obovate, apex acute, margin entire and glabrous, both surfaces glabrous. Stamens 10, strongly dimorphic. Larger (antesepalous) stamens 5, filaments 1.5-3.0 mm long, pink, pedoconnectives 1.9-2.9 mm long, pink, appendages 1.0-1.5 mm long, yellow, apex bilobate, thecae (excluding rostra) 1.0-1.5 mm long, purple, oblong, rostra 0.2-0.3 mm long, the circular pores ca. 0.2 mm wide. Smaller (antepetalous) stamens 5, filaments 1.5-2.0 mm long, pink, pedoconnectives 0.8-1.2 mm long, yellow, inconspicuous appendages ca. 0.1 mm long, yellow, apex emarginate, thecae (excluding rostra) 0.7-1.1 mm long, yellow, oblong, rostra 0.2-0.3 mm long, the circular pores ca. 0.2 mm wide. Ovary 1.8-2.0 mm long, 1.9-2.1 mm wide, globose, 3-5-locular. Style 3.7-4.2 mm long, pink. Capsules (at maturity) 2.5-3.4 mm long, 2.4-3.0 mm wide, globose, initially enveloped by the hypanthium, torus constricted at the apex, fruiting calyx tubes 0.3-0.4 mm long, fruiting calyx lobes 2.4-2.9 mm long, not thickened. Seeds not seen.

Distribution, habitat and elevation range.

Microlicia trembleyiformis is known from quartzitic campo rupestre, Cerrado and veredas (palm swamps) at Ouro Preto, Serra da Canastra, Uberlândia and Patrocínio (in Minas Gerais State) and campos de altitude in Serra Negra (Itatiaia), Rio de Janeiro State (Fig. 19B ). On Serra da Canastra, it was collected on sandy soils near streams, exposed to full sun, at elevations between 786 and 1300 m. Collections from Ouro Preto and Serra Negra lack additional habitat information.

Conservation.

This species is known from about 10 specimens. It is a little-collected species that, however, has a comparatively wide distributional range. The EOO is 92,214.048 km2, a value that would indicate a Least Concern conservation status if criterion B of IUCN (2019) was applied. However, the AOO of 24 km2 matches a status of Endangered in accordance with the same criterion. Both EOO and AOO requirements have to be fulfilled for the correct use of criterion B. Thus, we recommend a status of Least Concern (LC) for M. trembleyiformis . We suspect that this species occurs in low population densities. Some populations of M. trembleyiformis are protected in the Parque Nacional da Serra da Canastra.

Recognition and affinities.

Microlicia trembleyiformis can be recognised by its elliptic to ovate leaves that are 5-nerved from the base and solitary flowers with narrowly-triangular calyx lobes 1.5-2.1 mm long. In morphology, it is closest to M. parviflora and more distantly to M. altoparaisensis (see notes under these species for comparisons). Microlicia pentagona is the only congener that shares with M. trembleyiformis both the leaves 5-nerved from the base and solitary flowers. Microlicia trembleyiformis differs in having leaves that are papyraceous when dry (vs. chartaceous to coriaceous in M. pentagona ), the margin is ciliate with eglandular trichomes 0.1-0.4 mm long (vs. glabrous to minutely granulose) and the shorter calyx lobes are 1.5-2.1 mm long (vs. 6.2-8.5 mm long) and tenuous in fruit (vs. thickened). Amongst the compared species, only M. parviflora occurs in Ouro Preto, Serra da Canastra and Serra Negra, where sympatry with M. trembleyiformis is possible.

Notes.

According to Naudin (1845), this species was frequent in Ouro Preto Municipality, although we are not aware of any recent collections from that region. Naudin (1845) justified the placement of M. trembleyiformis in Microlicia because the type had 3-locular ovaries. Recent collections of M. trembleyiformis have 3-5-locular ovaries (e.g. Porto 2834). In the Parque Nacional da Serra da Canastra, M. trembleyiformis is known from only a few individuals that consistently have 3-locular ovaries ( Romero 2000).

Specimens examined.

Brazil. Minas Gerais: Capitólio Municipality, estrada para Cachoeira Fecho da Serra, Romero et al. 7550 (HUFU, US); Ouro Preto Municipality, [catal. B1, n° 160] Saint-Hilaire s.n. (lectotype: P [P002297746]!; isolectotype: F [F0360366]); São Roque de Minas Municipality, Serra da Canastra , Nakajima et al. 1476 (HUFU, US), Romero & Nakajima 3593 (HUFU, K, UEC), Romero 4157 (BHCB, F, HUFU), Santos 411 (HUFU, K); Serra do Salitre Municipality , Serra de Catiara , Duarte 2767 (BHCB, US); Uberlândia Municipality, Clube Caça e Pesca Itororó, Romero et al. 8689 (HUFU), Romero et. al. 8694 (HUFU); unknown municipality in Minas Gerais State, Glaziou 19221 (K, P) . Rio de Janeiro: Itatiaia Municipality, Serra Negra, Porto 2834 (NY, RB, US).

Figures

Figure 19. Geographic distribution of species of the Trembleya s. s. clade of Microlicia A distributions of M. altoparaisensis, M. calycina, M. chamissoana and M. flaviflora B distributions of M. laniflora and M. trembleyiformis.

Figure 29. Microlicia trembleyiformis A habit B detail of nodes and internodes C leaf abaxial surface D leaf adaxial surface E bracteole abaxial surface F floral bud G flower in lateral view H petal adaxial surface I antesepalous stamen J antepetalous stamen K gynoecium L capsule enveloped by the hypanthium. Drawn from Duarte 2767 (US).