Microlicia calycina (Cham.) Versiane & R.Romero, Bot. J. Linn. Soc. 197: 52. 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

2. Microlicia calycina (Cham.) Versiane & R.Romero, Bot. J. Linn. Soc. 197: 52. 2021.

Fig. 20

Trembleya calycina Cham., Linnaea 9(4): 430. 1835. basionym. Type: Brazil. "Brasilia, Itacolumi" [Minas Gerais, Ouro Preto], F. Sellow s.n. (lectotype, designated here: K [K00530658]!; isolectotypes: BR [BR0000005227020]!, F [neg. 16634]!, K [K00530659]!; image of lectotype is available at http://specimens.kew.org/herbarium/K000530659).

Trembleya revoluta Naudin, Ann. Sci. Nat., Bot. Sér. 3, 2: 155. 1844. Type: Brazil. "Minas Gerais, Capanema" [Minas Gerais, Santa Bárbara], 1841, P. Claussen 10 (lectotype, first-step designated by Martin and Cremers (2007), second-step designated here: P [P00723384]!; isolectotypes: G [G00368001]!, P [P00723507]!; image of lectotype is available at http://coldb.mnhn.fr/catalognumber/mnhn/p/p00723384).

Trembleya stenophylla Naudin, Ann. Sci. Nat., Bot. Sér. 3, 12: 265. 1849. syn. nov. Type: Brazil. "Minas Gerais, Capanema" [Minas Gerais, Santa Bárbara], 1843, P. Claussen 368 (lectotype, first-step designated by Martin and Cremers (2007), second-step designated here: P [P00723385]!; isolectotype: P [P00723386]!; image of lectotype is available at http://coldb.mnhn.fr/catalognumber/mnhn/p/p00723385).

Description.

Erect shrubs 0.65-1.5 m tall. Branchlets quadrangular, glandular-punctate and sparsely covered with glandular trichomes 0.1-0.2 mm long, light green (when fresh). Internodes 1.5-3.0 cm long, angles with narrow wings 0.2-0.4 mm wide. Petioles 0.8-1.8 mm long. Leaf blades 10-26 mm long, 2-9 mm wide, chartaceous (when dry), elliptic to narrowly elliptic, both surfaces green (when fresh), adaxial surface blackened and abaxial surface pale green (when dry), discoloured (when dry), base attenuate, apex rounded to acute, margin revolute, entire along the basal half, appearing entire to slightly serrulate on the upper half and minutely granulose and becoming glabrescent with age, 3-nerved from the base, one tenuous pair of acrodromal veins, tertiaries evident on the abaxial surface, nearly perpendicular to the mid-vein, little reticulate and branching apically, foveolate-like, adaxial surface sparsely glandular-punctate, appearing glabrous when dry, abaxial surface densely glandular-punctate. Inflorescences simple dichasia or reduced to solitary flowers, not congested. Bracts (including petioles) 1.0-1.3 cm long, 0.3-0.4 cm wide, 3-nerved, elliptic to narrowly elliptic, indumentum like that of the principal leaves. Bracteoles (at anthesis) sessile or with petioles up to 1.0 mm long, blades 4.0-5.0 mm long, 1.3-1.8 mm wide, elliptic, base attenuate, apex rounded to acute, margin entire and glandular-punctate, 1-nerved, indumentum like that of the principal leaves. Flowers 5-merous, pedicels (at anthesis) 0.5-0.7 mm long. Hypanthia (at anthesis) 2.6-3.5 mm long, 1.9-2.2 mm wide at the torus, campanulate, light green or reddish (when fresh), externally glandular-punctate. Calyx tubes 0.4-0.7 mm long. Calyx lobes (at anthesis) 3.5-5.2 mm long, 0.5-0.7 mm wide at the base, subulate, apex acuminate, margin entire, (when fresh) light green or reddish, externally glandular-punctate. Petals 7.8-10 mm long, 5.0-6.2 mm wide, magenta, obovate, apex acuminate, margin entire and glabrous, both surfaces glabrous. Stamens 10, strongly dimorphic. Larger (antesepalous) stamens 5, filaments 4.7-4.9 mm long, pink, pedoconnectives 5.9-6.2 mm long, pink, appendages 1.4-1.6 mm long, yellow, apex truncate to slightly emarginate, thecae (excluding rostra) 2.3-2.6 mm long, purple, oblong, rostra 0.4-0.7 mm long, the circular pores ca. 0.2 mm wide. Smaller (antepetalous) stamens 5, filaments 3.8-4.1 mm long, pink, pedoconnectives 0.6-0.8 mm long, yellow, inconspicuous appendages ca. 0.1 mm long, yellow, apex truncate, thecae (excluding rostra) 2.1-2.3 mm long, yellow, oblong, rostra 0.4-0.6 mm long, the circular pores ca. 0.2 mm wide. Ovary 2.0-2.2 mm long, 1.9-2.1 mm wide, globose, 5-locular. Style ca. 6.5 mm long, pink. Capsules (at maturity) 2.3-2.7 mm long, 2.3-2.7 mm wide, globose, initially enveloped by the hypanthium, torus constricted at the apex, fruiting calyx tubes 0.7-0.8 mm long, fruiting calyx lobes 5.5-6.0 mm long, not thickened. Seeds ca. 0.8 mm long, reniform.

Recognition and affinities.

Microlicia calycina may be recognised by its elliptic to narrowly elliptic leaf blades with revolute margins, 3-nerved from the base, simple dichasia or solitary flowers and subulate calyx lobes 3.5-5.2 mm long. In morphology, M. calycina resembles narrow-leaved forms of M. pentagona (see notes under this species). Both species share the glandular-punctate indumentum, inflorescences reduced to solitary flowers (sometimes perfect dichasia only in M. calycina ), subulate calyx lobes, magenta petals, and bicoloured anthers. Microlicia calycina differs by the leaf blades that are 3-nerved from the base (vs. 5-nerved) and calyx lobes 3.5-5.2 mm long (vs. 6.2-8.5 mm long) that become thick in fruit (vs. tenuous). These two species may occur sympatrically in the seasonally dry grasslands of Parque Estadual do Itacolomi ( Rolim 2011) and at Serra do Caraça. Microlicia parviflora is also morphologically similar to M. calycina , which may be distinguished by leaves 3-nerved from the base (vs. 5-nerved) and subulate calyx lobes (vs. triangular). Additionally, M. parviflora is distinct in having openly ramified inflorescences that are sometimes reduced to simple dichasia. In turn, the inflorescences of M. calycina consist of simple dichasia that are frequently reduced to solitary flowers. The distributions of Microlicia calycina and M. parviflora overlap in Caeté, Ouro Preto and Catas Altas, where sympatry is likely to occur. Microlicia calycina is also similar to M. pithyoides (see notes under this species).

Distribution, habitat and elevation range.

Endemic to central and southern Minas Gerais (Fig. 19A ), at Serra do Caraça, Serra do Itacolomi and Serra da Piedade. It occurs on quartzitic campo rupestre exposed to full sun at elevations between 1692 and 1920 m.

Conservation.

Microlicia calycina is known from about 20 collections. The EOO is 481 km2 and the AOO is 20 km2. This species is currently recognised as endangered (EN) by the Brazilian Government ( Brasília 2014). Based on IUCN (2019) recommendations and criteria, we recommend a similar assessment: (EN): B1ab(iii). The conservation units of Parque Estadual do Itacolomi and RPPN Serra do Caraça (Natural Heritage Private Reserve) are of Trembleya major importance for the long-term conservation of M. calycina .

Notes.

We agree with Cogniaux (1883-1888) and treat Trembleya revoluta as a synonym of M. calycina . The type of Trembleya revoluta (P. Claussen 10) differs from typical M. calycina collections only by its revolute leaf margins, a feature that appears to be an artefact of drying. Likewise, we consider Trembleya stenophylla a narrow-leaved form of M. calycina . Specimens of M. calycina with leaf blades conspicuously revolute have also been confused with M. pithyoides . For a comparison of M. calycina and M. pithyoides , see the notes under the latter.

Specimens examined.

Brazil. Minas Gerais: Caeté Municipality, Serra da Piedade, Grandi et al. 6593 (BHCB, HUFU); Catas Altas Municipality, Serra do Caraça, Castro et al. 283 (HUFU), Oliveira & Giacomin 47 (BHCB), Oliveira & Giacomin 84 (BHCB), Oliveira et al. 480 (BHCB), Pacifico & Bressan 296 (CAS, HUEM, SPF); Ouro Preto Municipality, Serra do Itacolomi , Barreto 9019 (BHCB, ESA, FUEL, HUFU, SP, SPF, UEC, UPCB), Damazio s.n. (RB [48391]), Glaziou 14745 (P), Glaziou 18232 (K, P, R), Pacifico & Bressan 291 (CAS, HUEM, SPF), Peron 220 (RB), Peron 268 (RB), Peron 269 (RB), Riedel s.n. (K [K00530657], NY [NY00941982], W [18890019737]), Rolim 366 (HUFU, NY, RB, VIC), Schwacke 9368 (RB, W); Unknown municipality, Claussen 10 (P [P00723384, P00723507]), “capanema”, Claussen 368 (P [P00723385, P00723386]), Sellow s.n. (lectotype: K [K00530659]; isolectotypes: BR [BR0000005227020], F [neg. 16634], K [K00530658]) .

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 20. Microlicia calycina A habit B leaf abaxial surface C bracteole abaxial surface D floral bud E flower in lateral view F flowering hypanthium G petal adaxial surface H antesepalous stamen I antepetalous stamen J gynoecium K capsule. Drawn from Barreto 9019 (UEC).