Microlicia chamissoana (Naudin) Versiane & R.Romero, Bot. J. Linn. Soc. 197: 53. 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

3. Microlicia chamissoana (Naudin) Versiane & R.Romero, Bot. J. Linn. Soc. 197: 53. 2021.

Fig. 21

Trembleya chamissoana Naudin, Ann. Sci. Nat., Bot. Sér. 3, 12: 270. 1849. basionym. Type: Brazil. "Brasilia, Itambé” [Minas Gerais, probably Santo Antônio do Itambé], F. Sellow s.n. [b. 1171 c. 1156] (lectotype, designated here: K [K00530656]!; isolectotype: P [P00723508]!; image of lectotype is available at http://specimens.kew.org/herbarium/K000530656).

Description.

Erect shrubs (0.1-)0.3-1.5 m tall. Branchlets quadrangular, glandular-punctate and covered with gland-tipped trichomes 0.2-0.4 mm long, light green (when fresh). Internodes 0.3-1.5 cm long, angles unwinged. Petioles 1.0-4.9 mm long. Leaf blades 10-28 mm long, 4-18 mm wide, chartaceous (when dry), elliptical, both surfaces green (when fresh), adaxial surface blackened and abaxial surface pale green (when dry), discoloured (when dry), base attenuate, apex obtuse to acute, margin flat or slightly revolute, entire throughout or slightly serrulate on the upper half and glandular-punctate, 7-nerved from the base, two pairs of acrodromous veins and one tenuous pair of veins close to the margin, tertiaries evident on the abaxial surface, nearly perpendicular to the mid-vein, reticulate and randomly branching, adaxial surface sparsely glandular-punctate, appearing glabrous when dry, abaxial surface densely glandular-punctate and covered with gland-tipped trichomes 0.2-0.4 mm long. Inflorescences simple or compound congested dichasia consisting of biparous cymes, or reduced to solitary flowers. Bracts (including petioles) 0.8-1.0 cm long, 0.6-0.7 cm wide, 5-nerved, elliptical, indumentum like that of the principal leaves. Bracteoles (at anthesis) with petioles 1.6-2.0 mm long, blades 4.2-4.9 mm long, 1.4-2.1 mm wide, narrowly elliptic, base attenuate, apex acuminate, margin entire along the basal half, sparsely serrulate on the upper half, 3-5-nerved, indumentum like that of the principal leaves. Flowers 5-merous, pedicels (at anthesis) 2-4 mm long. Hypanthia (at anthesis) 2.5-3.7 mm long, 1.9-2.1 mm wide at the torus, campanulate, reddish (when fresh), externally glandular-punctate and sparsely to densely covered with gland-tipped trichomes 0.2-0.4 mm long. Calyx tubes 0.9-1.2 mm long. Calyx lobes (at anthesis) 4.5-6.7 mm long, 1.9-2.1 mm wide at the base, narrowly triangular, apex acuminate, margin entire and sparsely ciliate with gland-tipped trichomes 0.2-0.4 mm long, (when fresh) reddish, externally glandular-punctate and covered with gland-tipped trichomes 0.2-0.4 mm long. Petals 11.5-13 mm long, 5.8-6.2 mm wide, magenta, obovate, apex acuminate, margin entire and glandular-punctate, adaxial surface sparsely glandular-punctate, abaxial surface glabrous. Stamens 10, strongly dimorphic. Larger (antesepalous) stamens 5, filaments 5.2-6.0 mm long, pink, pedoconnectives 5.5-6.5 mm long, pink, appendages 1.2-1.8 mm long, yellow, apex bilobate, thecae (excluding rostra) 1.7-2.6 mm long, purple, oblong, rostra 0.3-0.6 mm long, the circular pores ca. 0.3 mm wide. Smaller (antepetalous) stamens 5, filaments 4.7-5.0 mm long, pink, pedoconnectives 1.0-1.2 mm long, yellow, inconspicuous appendages ca. 0.1 mm long, yellow, apex truncate, thecae (excluding rostra) 1.5-2.0 mm long, yellow, oblong, rostra 0.4-0.6 mm long, the circular pores ca. 0.2 mm wide. Ovary 2.2-2.8 mm long, 1.6-1.8 mm wide, cylindrical, 5-locular. Style ca. 6.3 mm long, pink. Capsules (at maturity) 2.5-3.2 mm long, 2.3-3.0 mm wide, ovoid, initially enveloped by the hypanthium, torus constricted at the apex, fruiting calyx tubes 1.5-1.7 mm long, fruiting calyx lobes 5.2-6 mm long, not thickened. Seeds ca. 0.5 mm long, reniform.

Distribution, habitat and elevation range.

Largely restricted to the Serra do Cipó in central Minas Gerais (Fig. 19A ), but extending to the Serra dos Alves and probably to Pico do Itambé. Most of the recent collections were made at Serra do Cipó; only one collection studied came from Serra dos Alves, Souza & Miranda 1639 (BHCB). Considering Sellow’s itinerary in Brazil (see Rego et al. 2013), the type series was probably collected at the Pico do Itambé region. It occurs on quartzitic campo rupestre exposed to full sun at elevations between 1154 and 1462 m.

Conservation.

Microlicia chamissoana is known from fewer than 20 collections. The EOO is 885.927 km2 and the AOO is 32 km2. This species was collected on Pico do Itambé only in the 19th century and the local extinction of that population is a possibility. Several populations found more recently are protected in the Parque Nacional da Serra do Cipó. This species is already recognised as endangered (EN) by the Brazilian Government ( Brasília 2014). Our study based on IUCN (2019) recommendations and criteria reached a similar conclusion regarding its conservation status (EN): B1ab(iii).

Recognition and affinities.

Microlicia chamissoana may be recognised by its elliptic leaf blades with tertiaries densely reticulate and randomly branching, congested inflorescences or solitary flowers and narrowly triangular calyx lobes 4.5-5.7 mm long. It is probably more closely related to M. laniflora and M. pentagona , both of which may occur sympatrically with M. chamissoana at Serra do Cipó. Microlicia chamissoana differs from M. laniflora by the shorter height (0.1-)0.5-0.8 m tall (vs. 0.5-3.5 m tall), absence of lanose indumentum on branchlets, abaxial leaf surfaces and hypanthia (vs. present), leaves with shorter petioles 1.0-4.9 mm long (vs. 6-11 mm long), blades with tertaries densely reticulate and randomly branching (vs. little reticulate and branching apically), bracteoles with apices acuminate (vs. rounded), shorter hypanthia 2.5-3.7 mm long (vs. 5.0-6.5 mm long), shorter calyx lobes 4.5-6.7 mm long (vs. 7.9-9.7 mm long) and petals magenta (vs. white) 11.5-13.0 mm long (vs. 19.0-26.0). In turn, Microlicia chamissoana differs from M. pentagona by the branchlets, abaxial surfaces of the leaves and hypanthia that are densely glandular-punctate and covered with gland-tipped trichomes (vs. appearing glabrous, vernicose and minutely granulose), leaf blades with tertiaries densely reticulate and randomly branching (vs. parallel or little reticulate and branching apically) and calyx lobes tenuous (vs. thickened) 5.2-6.0 mm long (vs. 6.5-11.0 mm long).

Notes.

Major variation in M. chamissoana involves habit and degree of inflorescence development. This species is usually a shrub about 1 m tall, although an atypical specimen from Serra do Cipó is about 10 cm tall (A.M. Giulietti et al. CFSC12492). This specimen was described as a herb, but it has woody branches. Most of the specimens examined have congested, many-flowered inflorescences (e.g. Barreto 6745), although in some of the inflorescences, these are reduced to solitary flowers (e.g. Pacifico & Carmo 154, Almeda et al. 8580).

Based on F. Sellow s.n., Chamisso (1834: 396-397) provided a detailed description for M. chamissoana under Microlicia sp., indicating his uncertainty of its generic position, especially because of its 5-valvate capsules. Naudin (1849: 270) proposed the epithet Microlicia chamissoana for this species mentioning the description of Chamisso (1834: 396-397). Even preceded by a short description that is not diagnostic (5-valvate capsules), the name Trembleya chamissoana Naudin is still valid because Naudin (1849) made reference to Chamisso’s decription.

The type specimens of M. chamissoana , as cited by Cogniaux (1883-1888), have two collection numbers indicated on each of their labels (F. Sellow 1171 and 1156). Both collection numbers were cited by Cogniaux in "Flora brasiliensis". At least one set of Sellow’s duplicates of M. chamissoana was housed at B and probably destroyed during World War II. As the Sellow duplicate at K is in good shape, it is here designated as the lectotype for this species.

Specimens examined.

Brazil. Minas Gerais: “Itambé” [probably Santo Antônio do Itambé Municipality], Sellow s.n. (lectotype: K [K00530656]; isolectotype: P [P00723508]); Conceição do Mato Dentro Municipality, Serra do Cipó, Kameyama et al. CFSC10403 (SPF), Sheperd & Kirzenzaft 10214 (SP); Itabira Municipality, Serra dos Alves, Souza & Miranda 1639 (BHCB); Jaboticatubas Municipality, Serra do Cipo , Giulietti et al. CFSC12560 (SPF); Morro do Pilar Municipality , Serra do Cipo , Silveira s.n. (HUFU [56533]); Santana do Riacho Municipality , Serra do Cipo , Almeda et al. 8580 (CAS, HUEM, UEC), Escaramai et al. 52 (SPF), Giulietti et al. CFSC12492 (HUEM, SPF), Pacifico & Carmo 154 (HUEM), Pena & Viana 417 (SPF), Rocha 694 (BHCB), Romero et al. 8627 (HUEM, HUFU, RB), Semir CFSC5607 (SP); Unknown municipality, Serra do Cipo , Barreto 6745 (BHCB, HUFU, NY, SP, SPF, UEC, UPCB), Damazio 2026 (RB), Sena s.n. (W [W19110004181]) .

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 21. Microlicia chamissoana A habit B leaf abaxial surface C bracteole abaxial surface D floral bud E Flower in lateral view F flowering hypanthium G detail of the indumentum of the hypanthium H petal adaxial surface I gynoecium J antepetalous (behind) and antesepalous (in front) stamens. Drawn from Barreto 6745 (SPF, UEC).