Microlicia rosmarinoides (Mart. & Schrank ex DC.) Versiane & R.Romero, Bot. J. Linn. Soc. 197: 54. 2021.

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

9. Microlicia rosmarinoides (Mart. & Schrank ex DC.) Versiane & R.Romero, Bot. J. Linn. Soc. 197: 54. 2021.

Fig. 28

Trembleya rosmarinoides Mart. & Schrank ex DC., Prodr. 3: 125. 1828. basionym. Type: Brazil. "Habitat in summo Monte de V. Rica et in Itacolumi 5000 ped. alt. Provinciae Min. Gen." [Minas Gerais, Ouro Preto], C.F.P. Martius 808 (lectotype, designated here: M [M0165886]!; isolectotype: G [G00310213-online image]!).

Description.

Erect, densely branched shrubs 0.3-0.6 m tall. Branchlets quadrangular, glandular-punctate, light green (when fresh). Internodes 0.1-0.4 cm long, angles with narrow wings 0.2-0.3 mm wide. Petioles 0.5-1.2 mm long. Leaf blades 4-10 mm long, 1.0-1.9 mm wide, chartaceous (when dry), narrowly-lanceolate to narrowly-elliptic, both surfaces green (when fresh), adaxial surface blackened and abaxial surface pale green to pale brown (when dry), discoloured (when dry), base cuneate, apex rounded to acute, margin flat, entire and glandular-punctate, 1-nerved from the base, tertiaries little evident on the abaxial surface, adaxial surface glandular-punctate, abaxial surface glandular-punctate. Inflorescences reduced to solitary flowers on apical branches. Bracts absent. Bracteoles (at anthesis) with petioles 0.5-1.0 mm long, blades 2.5-3.3 mm long, 0.5-0.9 mm wide, lanceolate, base cuneate, apex acute to obtuse, margin entire, 1-nerved, indumentum like that of the principal leaves. Flowers 5-merous, pedicels (at anthesis) 0.4-0.6 mm long. Hypanthia (at anthesis) 2.2-3.5 mm long, 1.5-2.0 mm wide at the torus, campanulate to urceolate, light green (when fresh), externally glandular-punctate. Calyx tubes 0.3-0.5 mm long. Calyx lobes (at anthesis) 2.2-2.8 mm long, 0.5-0.8 mm wide at the base, subulate, apex acute, margin entire, (when fresh) light green, externally like the hypanthia. Petals 5.0-5.3 mm long, 2.4-3.0 mm wide, yellow, obovate, apex acute or rounded, margin entire and glabrous, both surfaces glabrous. Stamens 10, strongly dimorphic. Larger (antesepalous) stamens 5, filaments 2.2-3.0 mm long, yellow, pedoconnectives 3.2-3.8 mm long, yellow, appendages 0.8-1.0 mm long, yellow, apex emarginate to bilobate, thecae (excluding rostra) 1.4-1.7 mm long, yellow to orange, 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, yellow, pedoconnectives 0.8-1.0 mm long, yellow, inconspicuous appendages ca. 0.1 mm long, yellow, apex emarginate, thecae (excluding rostra) 1.4-1.6 mm long, yellow to orange, oblong, rostra 0.2-0.3 mm long, the circular pores ca. 0.2 mm wide. Ovary 0.9-1.1 mm long, 0.7-0.9 mm wide, ovoid, 5-locular. Style ca. 3 mm long, yellow. Capsules (at maturity) 2.5-3.5 mm long, 2.0-3.0 mm wide, globose, initially enveloped by the hypanthium, torus constricted at the apex, fruiting calyx tubes 0.3-0.6 mm long, fruiting calyx lobes 2.5-3.2 mm long, not thickened. Seeds 0.5-0.9 mm long, reniform.

Distribution, habitat, and elevation range.

Restricted to central Minas Gerais State (Fig. 25B ), where it is known only from Serra do Gandarela, Serra de Capanema, Serra de Ouro Preto, Serra de Itabirito, Belo Vale and Barão de Cocais. Microlicia rosmarinoides occurs in campo rupestre and canga, on ferruginous or quartzitic soils, exposed to full sun, at elevations between 1609 and 1807 m.

Conservation.

Microlicia rosmarinoides is a little-collected species, known from about 15 specimens. The EOO is 298.172 km2 and the AOO is 28 km2. Populations of M. rosmarinoides are protected in the Parque Nacional da Serra do Gandarela and probably in Parque Estadual do Itacolomi. Following IUCN (2019) criteria, we recommend an assessment of Endangered (EN): B1ab(iii) for this species.

Recognition and affinities.

Microlicia rosmarinoides can be readily recognised amongst congeners by its narrow leaves (1-1.9 mm wide) and flowers with yellow petals. The narrow leaves of M. rosmarinoides are more similar to those of the closely related M. pithyoides , while the yellow petals are shared only with the distantly related M. flaviflora . For comparisons, see notes under M. flaviflora and M. pithyoides .

Specimens examined.

Brazil. Minas Gerais: Barão de Cocais, Mina do Baú, Souza et al. 2584 (BHCB); Belo Vale , Occhioni et al. s.n. (RFA, US [US001900109]); Itabirito , Serra de Capanema , Carmo 192 (BHCB), Carmo 377 (BHCB); Ouro Preto municipality, Serra do Itacolomi , Martius 808 (lectotype: M [M0165886]; isolectotype: G [G00310213]), Pedrosa 110 (HUFU, OUPR), Schwacke 9184 (BHCB, RB, US, W); Rio Acima Municipality , Serra do Gandarela , Carmo 2262 (BHCB), Versiane & Castello 677 (HUFU, UEC), Vidal s.n. (BHCB [191426]); Santa Bárbara Municipality, Serra do Gandarela , Vidal s.n. (BHCB [181346]); Unknown municipality in Minas Gerais State, Glaziou 14747 (IAN, K, RB, US), Glaziou 19242 (K), Ule 2528 (US).

Figures

Figure 25. Geographic distribution of species of the Trembleya s. s. clade of Microlicia A distributions of M. parviflora and M. tridentata B distributions of M. pentagona, M. pithyoides and M. rosmarinoides.

Figure 28. Microlicia rosmarinoides A habit B detail of nodes and internodes C leaf abaxial surface D bracteole abaxial surface E floral bud F flower in lateral view G petal adaxial surface H antesepalous stamen I antepetalous stamen J capsule enveloped by the hypanthium K capsule in cross section L seed in lateral view. Drawn from Occhioni et al. s. n. (US [US 001900109]).