Lavoisiera scaberula Naudin (1844: 151)

Martins, Angela B. & Almeda, Frank, 2017, A Monograph of the Brazilian endemic genus Lavoisiera (Melastomataceae: Microlicieae), Phytotaxa 315 (1), pp. 448-450 : 448-450

36. Lavoisiera scaberula Naudin (1844: 151) . Type:— BRAZIL. Minas Gerais: “ Serro de Frio ( Diamantina ), lieux sablosseuses,” A.- C . Vauthier s.n. (holotype: P; isotypes: F!-frag., P!) .

= Lavoisiera microlicioides Naudin (1849: 221) . syn. nov. Type:— BRAZIL. Minas Gerais: “In Brasilia meridionali prov. Minas Geraes, 1841,” P. Claussen 22 (holotype: P- 05202125!; isotypes: BR-520178!, F!-frag., G!; photos of G isotype: F!, NY!).

= Lavoisiera uliginosa Cogniaux in A. & C. Candolle (1891: 88). syn. nov. Type :— BRAZIL. Minas Gerais: “In locis humidis Brasiliae prov. Minas Geraes ad Serra de Itabira do Campo,” 20 Dec. 1888, A. F. M. Glaziou 17514 (lectotype, here designated: BR!; isolectotypes, B destroyed, BM!, C!, F!, G!, LE!, P-723516-n.v., online image!, P-723517-n.v., online image!, RB!; photos of B isolectotype: F!, NY!).

= Lavoisiera itabirana Hoehne (1922: 33) . syn. nov. Type:— BRAZIL. Minas Gerais: “ Pico de Itabira ,” 19 Dec. 1916, P. Campos Porto 557 (holotype: RB!; isotype: BHCB ex BHMH!) .

Erect subshrubs 0.7–1.2 m tall. Branches and branchlets subquadrangular to quadrisulcate when young, furrowed longitudinally on opposite faces, sparsely to copiously beset with short (0.25 mm long) gland-tipped trichomes, older branches glabrescent, defoliating and decorticating at the base and becoming rounded to subrounded with age; internodes 3–5 mm long, with knobby thickenings that persist where a leaf has fallen away, nodes with short, vinaceous glandular trichomes. Leaves sessile, semi-amplexicaul, spreading to laxly imbricate toward the tips of young branchlets, blade 3–8 × 3–6 mm, membranaceous, ovate to elliptic, base rounded to subcordate, apex obtuse and shortly mucronulate, margin serrulate to subcrenulate and glandular-ciliolate, the glandular cilia 0.7 mm long, adaxial surface glabrous except for a few glandular trichomes at the blade margins and/or on the apical third of the blade, sparsely to moderately beset on the abaxial surface with gland-tipped trichomes 0.25–0.5 mm long that are often concentrated at the base of the midvein, the glands frequently caducous, flat, yellowish-green, 3-nerved. Flowers 6-merous, solitary, terminal on principal and secondary branchlets but becoming central or pseudolateral with the elongation of lateral shoots, sessile. Bracts 6–8, subsessile to sessile, 6 × 5 mm, ovate-suborbicular, base rounded to subcordate, apex acute, margins serrulate-ciliate, 5-nerved, mostly similar to the principal leaves. Hypanthium (at anthesis) 3–3.5 mm long, broadly campanulate, 3.5–4 mm wide at the apex, constricted above the ovary, sparsely glandular-puberulous under the constriction and toward the base, glabrous distally. Calyx tube inconspicuous to ca. 0.5 mm long; calyx lobes (at anthesis) 4–6 × 1–1.5 mm, membranaceous, caducous, narrowly triangular to linear-oblong, apex acute and tipped with a glandular trichome, margins glandular-ciliate, sparsely glandular-hirtellous abaxially, glabrous adaxially, tardily caducous. Petals 10–15 × 6–8 mm, pink with a cream base, obovate, apex obtusely apiculate with a gland-tipped trichome, base attenuate, margins obscurely and sparsely glandular-ciliolate. Stamens 12, dimorphic, completely yellow: large (antesepalous) stamens 6, filaments 4–5 mm long, anther thecae 2.5 × 1 mm, linear-oblong, rostrum ca. 0.3 mm long, pedoconnective 3–4 mm long, appendage ca. 1 mm long, inconspicuously bilobed; small (antepetalous) stamens 6, filaments 4 mm long, anther thecae 2 × 0.7 mm, linear-oblong, rostrum ca. 0.3 mm long, pedoconnective 1–2 mm long, appendage 1 mm long,

LAVOISIERA ( MELASTOMATACEAE )

Phytotaxa 315 (1) © 2017 Magnolia Press • 159 rounded to inconspicuously lobed. Ovary 2- or 4-locular, 4/5 inferior, style 4–6 mm long, declinate, glabrous, stigma punctiform. Fruiting hypanthium (including calyx lobes) 4–6 mm long. Capsule (at maturity) 3–4.5 × 2.5–3.5 mm, oblong, enveloped by the persistent hypanthium, dehiscing from the base to the apex. Seeds 0.57–0.70 × 0.38–0.49 mm, oblong-arcuate, light yellowish-brown, periclinal cell walls of the testa concave (foveolate), raphal zone 40–50% the length of the seed. Chromosome number unknown.

Illustrations:— Figure 59 ; Cogniaux (1883: t. 36).

Phenology:—Collected in flower and post-mature fruit in September, October, December, January, February, April, and August.

Distribution and habitat:—Endemic to Minas Gerais where it is widespread but local and uncommon on the Cadeia do Espinhaço from the vicinity of Ouro Preto and Pico de Itabira north to the Diamantina region in damp sandy places and rocky outcrops of campo rupestre at 680–1600 m. Figure 20 .

Conservation status:—The known collections of this species, several of which were made in the last two decades, come from a scattering of localities along the southern Cadeia do Espinhaço. Precise geographic coordinates are available for about half of the localities but we have no information on the size of any of the populations. The EOO is 7,359.134 km ² and the AOO is 52 km ². None of the known populations appears to occur in a protected area. Some are close to the northern boundary of Parque Nacional Serra do Cipó and may eventually be discovered within that park. In view of the periodic fires throughout its range and its fragmented population structure we assign this species a classification of Vulnerable (VU): B2ab(iii).

Discussion:— Lavoisiera scaberula is readily identified by its relatively small (3–8 × 3–6 mm) abaxially glandular-puberulent leaf blades, glandular-puberulent uppermost cauline internodes, 6-merous flowers, and 2- or 4-locular ovary. All of the species here relegated to synonymy are essentially identical to L. scaberula in ovary locule number and in vegetative and floral details but with leaf dimensions that tend toward the lower end of the variation spectrum. Although there is a tendency for ovary locule number to be consistent within a population, Irwin et al. 19887 from Serra de Itabirito , has both 2- and 4-locular ovaries. The overall homogeneity in vegetative and floral characters coupled with this kind of intrapopulational variation in ovary locule number provides what we believe to be a strong rationale for recognizing only one taxonomic species.

The closest relative of L. scaberula appears to be L. mucorifera . These two species share 6-merous flowers and the glandular-puberulent indumentum on leaf blades and cauline internodes. The latter, which appears to be restricted to the Diamantina region of the Cadeia do Espinhaço, differs in its consistently 6-locular ovary and modally longer (to 18 mm) leaves that are mostly elliptic-lanceolate to elliptic-ovate with an indumentum that is typically evenly distributed on both foliar surfaces.

Additional specimens examined:— MINAS GERAIS: Mpio. Nova Lima, Morro do Chapéu, Andrade & Siqueira 1386 (BHCB!); Mpio. Nova Lima, Morro do Chapéu, Andrade 22 (BHCB!); Serra de Itabirito , ca. 45 km SE of Belo Horizonte, Irwin et al. 19887 (NY!, US!); Santana do Riacho, Pico do Breu, -19.644, -43.415, Kinoshita & Yamamoto 2222 (UEC!); Belo Horizonte, Serra do Curral, -19.920, -43.937, Krieger s.n. (CESJ, MBM); Mpio. Santana do Riacho, Serra do Cipó, Mello Barreto 7027 (BHCB ex BHMH!); Pico de Itabirito, Palacios et al. 3842 (R!); Congonhas do Norte, Serra Talhada , -18.87, -43.737, Pirani 4097 (SPF!); Santana do Riacho, Serra do Cipó, -19.101, -43.676, Pirani 5518 (SPF); Mpio. Nova Lima, Morro do Chapéu, -19.985, 43.846, Ranieri s.n. (UEC!); Serra do Cipó, Lapinha, estrada para Brumas do Espinhaço, -19.066, -43.706, Romero et al. 8667 (HUEM); Santana do Riacho, ao longo do Rodovia Belo Horizonte-Conceição do Mato Dentro, Km 137 antigo, -19.168, -43.714, Semir CFSC 5610 (UEC!); Serra de Itabira do Campo, Schwacke s.n. (BR!, R!, RB!, US!); Mpio. Gouveia, Rodovia Curvelo-Diamantina, ca. 26 km de Gouveia em direção a Curvelo, 18°34’46.9”S, 43°52’29.8”W, Souza et al. 21004 (CAS!, ESA, MBM, SPF, UEC); Santana de Pirapama, Serra do Cipó, Serra da Lapa , Distrito de São José da Cachoeira, -19.002, -43.452, Souza et al. 32586 (UEC!); Santana de Pirapama, Serra do Cipó, início da trilha da Senhorinha, -18.963, -43.775, Zappi 1602 (SPF!); Mpio. Datas, estrada Datas-Serro, povoado de Trinta Réis, Zappi et al. CFCR 10672 (SPF!, US!). MINAS GERAIS?: exact locality not specified, Glaziou 17514 (LE!).

160 • Phytotaxa 315 (1) © 2017 Magnolia Press

MARTINS & ALMEDA LAVOISIERA ( MELASTOMATACEAE )

Figures

FIGURE 20. Distributions of Lavoisiera angustifolia, L. belinelloi, L. bradeana, L. punctata, L. sampaioana, L. scaberula, and L. tetragona.

FIGURE 59. Lavoisiera scaberula. A. Habit. B. Abaxial leaf surface with enlargement of surface detail (right). C. Abaxial bract surface. D. Hypanthium and calyx lobes. E. Petal showing enlargement of apex detail (above). F. Ventral view of antesepalous stamen. G. Ventral view of antepetalous stamen. H. Ovary cross-section. I. Seed. (Based on: A, B, D, E, H, I, Irwin et al. 19887, US; C, F, G, Zappi et al. CFCR 10672, US.)