Microlicia pentagona (Naudin) 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

7. Microlicia pentagona (Naudin) Versiane & R.Romero, Bot. J. Linn. Soc. 197: 54. 2021.

Fig. 26

Trembleya pentagona Naudin, Ann. Sci. Nat., Bot. Sér. 3, 2: 154. 1844. basionym. Type: Brazil. "In montibus vulgo Serra d’Ouro Branco, provincia Minas-Geraes" [Minas Gerais, Ouro Branco], A. Saint-Hilaire s.n. (lectotype, first-step designated by Martin and Cremers (2007), second-step designated here: P [P00723399]!; isolectotype: P [P00723398]!; image of lectotype is available at http://coldb.mnhn.fr/catalognumber/mnhn/p/p00723399).

Description.

Erect shrubs or treelets 0.5-1.5 m tall. Branchlets quadrangular, appearing glabrous, vernicose and minutely granulose, vinaceous (when fresh). Internodes 0.4-2.5 cm long, angles unwinged. Petioles 1.8-2.4 mm long. Leaf blades 12-40 mm long, 3-15 mm wide, chartaceous to coriaceous (when dry), elliptic, ovate, narrowly elliptic or linear, both surfaces green (when fresh), adaxial surface blackened and abaxial surface pale green to pale brown (when dry), discoloured (when dry), base cuneate to attenuate, apex rounded to acute, margin flat, entire along the basal half, serrulate on the upper half and minutely granulose and becoming glabrescent with age, 5-nerved from the base, one pair of acrodromous veins and one pair of tenuous veins close to the margin, tertiaries little evident on the abaxial surface, nearly perpendicular to the mid-vein, parallel or little reticulate and branching apically, adaxial surface glabrous to minutely granulose, vernicose, abaxial surface glabrous to minutely granulose, vernicose. Inflorescences reduced to solitary flowers apically on the branches. Bracts absent. Bracteoles (at anthesis) with petioles 1.8-3.0 mm long, blades 3.0-6.5 mm long, 1.1-3.6 mm wide, elliptic, ovate or lanceolate, base attenuate to cuneate, apex acute to obtuse, margin entire, 3-nerved, indumentum like that of the principal leaves. Flowers (4-)5-merous, pedicels (at anthesis) 0.8-2.0 mm long. Hypanthia (at anthesis) 2.5-3.5 mm long, 2.7-3.0 mm wide at the torus, campanulate to urceolate, light green or reddish (when fresh), externally glabrous, minutely granulose, vernicose. Calyx tubes 0.2-0.4 mm long. Calyx lobes (at anthesis) 6.2-8.5 mm long, 1.8-2.2 mm wide at the base, subulate, apex acute, margin entire, (when fresh) light green or reddish, externally like the hypanthia. Petals 11.8-13.8 mm long, 7.1-9.5 mm wide, magenta, obovate, apex shortly acuminate, margin entire and glabrous, both surfaces glabrous. Stamens (8)10, strongly dimorphic. Larger (antesepalous) stamens (4)5, filaments 4.0-5.0 mm long, pink, pedoconnectives 5.3-5.8 mm long, pink, appendages 1.2-1.6 mm long, yellow, apex emarginate to bilobate, thecae (excluding rostra) 1.2-2.0 mm long, vinaceous, oblong, rostra 0.5-0.7 mm long, the circular pores ca. 0.2 mm wide. Smaller (antepetalous) stamens (4)5, filaments 3.9-4.4 mm long, pink, pedoconnectives 1.0-1.6 mm long, yellow, inconspicuous appendages ca. 0.1 mm long, yellow, apex emarginate, thecae (excluding rostra) 1.6-2.0 mm long, yellow, oblong, rostra 0.5-0.6 mm long, the circular pores ca. 0.2 mm wide. Ovary 2.5-2.7 mm long, 2.4-2.6 mm wide, globose, 5-locular. Style 6.0-6.6 mm long, magenta. Capsules (at maturity) 4.5-5.5 mm long, 5.0-6.0 mm wide, globose, initially enveloped by the hypanthium, torus constricted at the apex, fruiting calyx tubes 0.2-0.4 mm long, fruiting calyx lobes 6.5-11.0 mm long, stout, thickened. Seeds 0.5-0.7 mm long, reniform.

Distribution, habitat and elevation range.

Endemic to Minas Gerais State (Fig. 25B ) in Serra do Caraça, Serra do Cipó, Serra de Ouro Preto, Serra de Ouro Branco, Serra do Itabirito, Mariana and Barão de Cocais. It occurs on quartzitic and ferruginous campo rupestre, exposed to full sun, at elevations of about 1000-1830 m.

Conservation.

Microlicia pentagona is known from about 70 collections. The EOO is 2,667.623 km2 and the AOO is 56 km2. Several populations are protected within the following conservation units: Parque Estadual do Itacolomi, Parque Estadual Serra do Intendente, Parque Estadual Serra do Ouro Branco, Parque Nacional da Serra do Cipó and RPPN Serra do Caraça (Natural Heritage Private Reserve). Following the IUCN (2019) recommendations and criteria, we recommend an Endangered (EN): B1ab(iii) status for this species.

Recognition and affinities.

Microlicia pentagona can be recognised by its branches, leaves and hypanthia that are glandular-punctate and vernicose, leaves 5-nerved from the base with one pair of acrodromous veins and one pair of tenuous veins close to the margin, inflorescences reduced to solitary terminal flowers and calyx lobes 6.2-8.5 mm long that become thickened in fruit. The elongate calyx lobes of M. pentagona are comparable in length only to those of M. laniflora (7.9-9.7 mm long) and are consistently longer than those of all remaining congeners. In fruit, the thickened calyx lobes of M. pentagona are unique in the clade. Overall, M. pentagona is morphologically similar to M. calycina , M. chamissoana , M. laniflora and M. parviflora . For comparisons, see comments under these species.

Notes.

Microlicia pentagona is remarkably variable in leaf shape and size. The leaf blades vary from almost linear (e.g. Irwin et al. 20537, Barreto 10734) to narrowly elliptic (e.g. Barreto 7025, Joly et al. CFSC 3196) and elliptic (e.g. Silva 1043). Examples of variation in leaf size are Almeda et al. 9203 (1.7-2.1 cm long) and Silva 1043 (2.3-3.1 cm long). Some modal extremes were informally recognised as distinct taxa by Mello Barreto on herbaria labels. As no character varies in a meaningful way, we agree with Martins (1997) and treat all these extremes within the variation here attributed to M. pentagona .

Specimens examined.

Brazil. Minas Gerais: Barão de Cocais Municipality, Brandão 20838 (HUFU); Catas Altas Municipality, Serra do Caraça, Hatschbach et al. s.n. (HUFU [25601]), Irwin et al. 29213 (NY), Oliveira et al. 478 (BHCB), Oliveira et al. 480 (BHCB, RB), Oliveira et al. 518 (BHCB), Silva et al. 1043 (HUFU), Sobral et al. 14508 (HUFSJ, RB); Santa Bárbara Municipality [ “Capanema”], Claussen 296 (W), Vainio 33501 (US); Jaboticatubas Municipality [ “Caeté”], Serra do Cipo , Magalhães 2278 (BHCB, US); Mariana Municipality, Pivari et al. 2512 (BHCB); Ouro Branco Municipality, Saint-Hilaire s.n. (lectotype: P [P00723399]; isolectotype: P [P00723398]); Ouro Preto Municipality, Antônio-Silva et al. 315 (HUFU, OUPR), Bortoluzzi et al. 678 (RB, VIC), Damazio s.n. (RB [48352], NY [NY00942037]), Michelangeli et al. 1580 (NY, UPCB), Pacifico & Bressan 294 (HUEM, SPF), Peron 256 (RB), Peron 260 (RB), Rezende 507 (HUFU), Rolim et al. 353 (UPCB, VIC), Rolim et al. 361 (NY, RB, VIC), Rolim et al. 370 (HUFU, NY, RB, VIC), Schwacke 10814 (W), Schwacke 9325 (RB, W); Santa Bárbara Municipality, Serra do Caraca , Almeda et al. 7751 (CAS, HUFU, UEC), Damazio s.n. (RB [48392]), Ordones et al. 213 (BHZB, HUFU), Pirani & Yano 692 (RB, SP, SPF), Rapini et al. 296 (HUEM, SP, SPF), Romero et al. 5303 (CAS, UEC); Santana do Riacho Municipality , Serra do Cipo , Almeda et al. 8555 (CAS, UEC), Almeda et al. 8911 (CAS, UEC), Almeda et al. 9203 (CAS, HUEM, UEC), Barreto 1182 (RB), Contro & Marques 21 (HUEM, HUFU), Duarte 2004 (FLOR, MBM, RB), Fernandes s.n. (HUFU [56535]), Irwin et al. 20178 (CAS, MO, NY, UEC, US), Irwin et al. 20486 (CAS, MO, NY, US), Irwin et al. 20537 (CAS, NY, UEC, US), Pacifico & Bressan 531 (CAS, HUEM, RB). Romero & Nakajima 5998 (HUEM, HUFU, UEC), Semir CFSC5608 (SP, SPF), Semir & Sazima CFSC3395 (UEC); Santana do Riacho Municipality [ “Conceição do Mato Dentro"], Serra do Cipo , Barreto 7025 (BHCB, HB, UEC); Santana do Riacho Municipality [ “Jaboticatubas”], Serra do Cipo , Giulietti & Menezes 4017 (SP, SPF, UEC), Hatschbach et al. 28759 (MBM, SPF, US), Hatschbach et al. 29958 (MBM), Joly & Semir CFSC2957 (UEC), Joly & Semir CFSC3196 (SPF, UEC), Sazima CFSC4259 (RB, SP, UEC), Semir & Joly CFSC3743 (UEC); Santana do Riacho Municipality [" Santa Luzia "], Serra do Cipo , Barreto 10734 (HB, UEC), Barreto 7023 (BHCB), Barreto 7024 (UEC), Brade 14756 (R), Duarte 2692 (R, RB, US); Unknown municipality in Minas Gerais State, Casaretto s.n. (G [G00318565]), Claussen 1617 (P), Claussen 1637 (P), Claussen 22 (P, US), Claussen 350 (W), Claussen s.n. (P [P005317034], P [P005317035]), Glaziou 14742 (K, NY, P, R), Ule 2543 (US), Schüch s.n. (W [70510]) .

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 26. Microlicia pentagona 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 (left) and antepetalous (right) stamens I gynoecium J capsule enveloped by the hypanthium. Drawn from Sazima CFSC 4259 (UEC) and Almeda et al. 9203 (UEC).