Microlicia candolleana R. Romero & Versiane, 2016

Romero, Rosana & Versiane, Ana Flavia Alves, 2016, Microlicia candolleana (Melastomataceae): a new endemic species to the Espinhaço range, Minas Gerais, Brazil, Phytotaxa 261 (3), pp. 275-281 : 276-280

Microlicia candolleana R. Romero & Versiane , spec. nov. ( Figs. 1–2 )

Type:— BRAZIL. Minas Gerais: Serra do Cipó, estrada Lagoa Santa-Conceição do Mato Dentro , km 118, solo pedregoso, 23 February 1995, N. M. Castro 428 (holotype HUFU!; isotypes BHCB!, K!, P!, RB!, UEC!) .

Erect subshrub or shrub, 0.5–1 m tall, few branched. Branches quadrangular, 4-winged; older branches leafless. Branches, leaves, pedicels, hypanthium and sepals with indumentum of spherical, golden glands, glutinous. Leaves sessile, ascending, spreading, discolorous, drying green or brownish; blade oval-lanceolate, 5.5–12 × 3–9 mm, apex acute, base cordate or rounded, margin entire or slightly crenulate, 3–7-nerved from base, nerves evident on both surfaces, the marginal pairs not reaching the apex. Flowers solitary, lateral and terminal, condensed at the apex of the branches, 5-merous, zygomorphic as a result of the position of stamens and style; pedicel 0.5–1 mm long, with sparse trichomes. Hypanthium oblong to oblong-campanulate, slightly striate, 3–5 × 2–5 mm, drying green-brownish; calyx tube 0.5–0.8 mm long; sepals subulate, 3–7 × 0.5–1 mm, apex acute, sepals longer or with the same length hypanthium. Petals oblong, 5.5–12.5 × 3–5.5 mm, pink or purple, apex rounded to acute, margin entire, glabrous. Stamens 10, dimorphic in size and shape, thecae tetraesporangiate; larger stamens 5, filaments 2.5–5 mm long, anthers oval-oblong, 3–3.5 mm long (including beak), pink, beak 0.5–0.7 mm long, connective prolonged 1.5–3.5 mm long, ventral appendage 1.5–2 mm long, expanded, truncate, retuse to slightly bilobed; smaller stamens 5, filaments 2.5–5.5 mm long, anthers oval-oblong, 2–2.5 mm long (including beak), yellow, beak 0.2–0.5 mm long, connective prolonged 0.5–1.5 mm long, ventral appendage ca. 0.2 mm long, retuse to bilobed. Ovary oblong, 2–3.5 × 2–2.5 mm, superior, 3-locular, glabrous; style terete, 3.5–10 mm long, pink, stigma punctiform. Capsule oblong to subglobose, 5–6 × 3–4 mm, brown, with ovary apex slightly exposed, dehiscing into 3 valves from the apex, hypanthium covering the entire ovary and peeling off as the fruit matures. Seeds 1–1.5 × ca. 0.5 mm, half slightly curved to one side, pale brown, numerous, testa foveolate.

Distribution and habitat:—Endemic to Serra do Cipó, Minas Gerais, Brazil, occurring in rocky fields on sandy soil with outcrops, ca. 1,200 m elevation ( Fig. 3 ). Microlicia candolleana is a well-collected species with 27 herbarium samples collected during the last 80 years.

Additional specimens examinated:— BRAZIL. Minas Gerais: Serra do Cipó, Santa Luzia , km 116, 13 January 1934, H. L. Mello Barreto 7019 ( BHCB, HUFU, UEC) ; ibidem, 15 January 1951, A. Macedo 2966 ( US) ; ibidem, 18 August 1957, M. Magalhães 9709 ( US) ; ibidem, Chapéu de Sol , December 1958, A. P. Duarte 4539 ( US) ; ibidem, between km 111 and 128 on road from hotel Chapéu de Sol , 4000 ft., 20 December 1959, B. Maguire & C. K. Maguire 44708 A ( NY, US) ; ibidem, km 118, 14 February 1963, A. P. Duarte 7652 ( NY) ; ibidem, 16 March 1964, E. Pereira 8905 ( US) ; ibidem, ca. 120 km (ca. 145 km N of Belo Horizonte ), 1,200 m elev., 14 February 1968, H. S. Irwin et al. 19983 ( MO, NY, UB, US) ; ibidem, ca. 120 km (ca. 145 Km N of Belo Horizonte), 1,300 m elev., 15 February 1968, H. S. Irwin et al. 20157 ( NY, UB, US) ; ibidem, 32 km north of Almeida , 16 January 1972, L. B. Smith & E. S. Ayensu 15945 ( US) ; Ibidem, Jaboticatubas , 17 January 1972, G. Hastchbach et al. 28676 ( MBM, US) ; Ibidem , 17 January 1972, G. Hastchbach et al. 28727 ( MBM, US) ; ibidem, ca. 1,125 m, 18 February 1972, W. R. Anderson 36236 ( NY, UB, US) ; ibidem, Santana do Riacho , 24 October 1974, G. Hastchbach et al. 35311 ( MBM, US) ; ibidem, 2 km beyond Chapéu de Sol , 3300 ft., 30 January 1980, R. M. King & F. Almeda 8360 ( MO, US, UB) ; ibidem, estrada da usina, 9 January 1981, N. M. Castro s.n. ( HUFU 266 ) ; ibidem, ca. 4–5 km N of Chapéu de Sol , 3000 ft., 15 January 1981, R. M. King & L. E. Bishop 8462 ( MO, UB, US) ; ibidem, near Hotel Chapéu de Palha , ca. 1,200 m elev., 16 January 1989, S. S. Renner 2122 ( US) ; ibidem, Santana do Riacho, Estrada Lagoa Santa-Conceição do Mato Dentro , km 110, 8 June 1989, A. A. A. Barbosa s.n. ( HUFU 2238 ) ; ibidem, 10–20 km NE de Cardeal Mota, camino a Conceição do Mato Dentro , 19°20’S, 43°35’W, 15 May 1990, M. M. Arbo et al. 4180 ( CTES, SPF, US) ; ibidem, 7 km NE de Cardeal Mota, camino a Conceição do Mato Dentro , 19°20’S, 43°35’W, 8 February 1991, M. M. Arbo et al. 4617 ( CTES, US) ; ibidem, 11 km NE de Cardeal Mota, camino a Conceição do Mato Dentro , 19°20’S – 43°35’W, 8 February 1991, M. M. Arbo et al. 4679 ( CTES, US) ; ibidem, Santana do Riacho, próximo do córrego do Palácio , 16 February 1995, H. C. de Sousa 69 ( HUFU, OUPR) ; ibidem, Santana do Riacho, rodovia Belo Horizonte-Conceição do Mato Dentro, ca. 4 km após o Córrego Chapéu de Sol , 12 January 1996, V. C. Souza et al. 10182 ( ESA, HUFU, UPCB) ; ibidem, Jaboticatubas, entre km 112 e 113 na estrada para Conceição do Mato Dentro , 19°10’S, 43°30’W, 31 May 1998, F. Almeda et al. 7758 ( HUFU) ; ibidem, Rodovia Cardeal Mota-Conceição do Mato Dentro , km 110, 19º17’21”S, 43º34’14”W, 1,250 m elev., 30 June 2015, R. Romero et al. 8614 ( HUFU) .

Conservation status:—Based on georeferenced data from cited collections, the area of occupancy was calculated using GeoCAT ( Bachman et al. 2011). Due to the restricted extent of occurrence and area of occupancy (AOO= 12 km ²), M. candolleana should be considered endangered EN B1b(iii)+2b(iii) according to the IUCN Categories and Criteria (2012). Most collections of M. candolleana were made in areas of rocky fields from Serra do Cipó next to the highway MG 010. Only one collection was made within the confines of the National Park of Serra do Cipó, a natural reserve maintained by federal government. At least inside this conservation unit, the species is protected since the region has suffered the environmental impacts of tourism and the growing iron extraction ( Gontijo 2003).

Etymology:—The specific epithet was chosen to honor Augustin Pyramus de Candolle (1771–1841), the Swiss botanist that authored the first seven volumes of Prodromus Systematis Naturalis Regni Vegetabilis , a monumental work of 17 volumes which deals with all known seed plants including taxonomy and biogeography.

Discussion:— Microlicia candolleana R. Romero & Versiane is morphologically similar to M. amplexicaulis Cogniaux (1883: 82) and M. obtusifolia Cogn. ex R. Romero (2003: 116) , which are also endemic to Espinhaço range in Minas Gerais state. The latter two are subshrubs occurring exclusively in rocky fields from Diamantina Plateau. The three species have an indumentum of spherical, golden glands on the branches, leaf blade, and pedicels. Recent studies have revealed that these glands have a short stalk ( Romero et al. 2015, 2016b).

Microlicia candolleana and M. amplexicaulis have sessile leaves, oval-lanceolate blade with indumentum of spherical, golden glands, visible nerves on both surfaces, pedicellate flowers with pink petals and dimorphic stamens with tetrasporangiate and bicolorous anthers. However, M. amplexicaulis differs in having flowers with a longer pedicel, hypanthium strongly striated and triangular sepals ( Cogniaux 1883) ( Table 1).

Microlicia candolleana also resembles M. obtusifolia since they have oval-lanceolate leaves, branches, both surfaces of the leaves, and pedicels with indumentum of spherical, golden glands, flowers with pink petals, and subulate sepals. The stamens are also dimorphic with tetrasporangiate and bicolorous anthers. However, the indumentum of spherical long-stalked glandular trichomes on the hypanthium apex and sepals easily distinguishes M. obtusifolia from M. candolleana (see Romero 2003).

Figures

FIGURE 1. Microlicia candolleana. A. Branch. B. Leaf abaxial surface showing indumentum of spherical glands. C. Floral bud. D. Flower branch. E. Petal with rounded apex. F. Petal with acute apex. G–J. Lateral views of the stamens showing variations in the ventral appendage. G. Small stamen with retuse appendage. H. Large stamen with truncate appendage. I. Small stamen with bilobed appendage. J. Large stamen with bilobed appendage. K. Gynoecium. L. Capsule covered by the hypanthium that peels off at maturity (A–E, H, and K from N.M. Castro 428; F from H.S. Irwin et al. 19983; I from A.A.A. Barbosa s.n. (HUFU 2238); J from W.R. Anderson et al. 36236; L from M.M. Arbo et al. 4180).

FIGURE 2.A–C. Microlicia candolleana (R. Romero et al.8614). A. Habitat next to the highway MG 010, Cardeal Mota to Conceição do Mato Dentro. B. Vegetative branch showing sessile and ascending leaves. C. Mature flower without petals and stamens. (Photos:R. Romero).

FIGURE 3. Distribution of Microlicia candolleana (red circle).