Lavoisiera sampaioana Barreto (1935c: 10–11)

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

35. Lavoisiera sampaioana Barreto (1935c: 10–11) . Type :— BRAZIL. Minas Gerais: “Habitat in civitate Minas Geraes, in campis siccis arenosisque in Serra do Cipó, secus margine viae ad vicum Morro do Pilar, ubi frequentissima,” 3 February 1934, A. J. Sampaio 6579 (holotype: R-28764!; isotypes: R-28764a-n.v., online image!, R-28764b-n.v., online image!, R-28764c-n.v., online image!, R-28764d-n.v., online image!).

= Lavoisiera sampaioana var. parvifolia Barreto (1935c: 11) . syn. nov. Type :— Brazil. Minas Gerais: “Habitat in eodem loco indicato in saxosis,” 3 February 1934, A. J. Sampaio 6578 (holotype: R-28765!; isotypes: R-28765a-n.v., online image!, R-28765b-n.v., online image!, R-28765c-n.v., online image!, R-28765d-n.v., online image!).

Erect, dichotomous or sometimes much-branched and densely fastigiate shrubs (0.5–) 1–1.5 m tall. Branches and branchlets subquadrangular to subrounded, furrowed longitudinally on opposite faces, rigid, glabrous, occasionally leafy to the base or defoliating basally with age; internodes 2–4 mm long, with knobby thickenings that persist where a leaf has fallen away, nodes with conspicuous leaf scars and inconspicuous puberulous-glandular trichomes. Leaves sessile to subsessile, densely imbricate and concealing the internodes, congested at the ends of branchlets; petiole inconspicuous, flattened, 0.5–1 mm long; blade 9–14 × 6–10 mm, coriaceous, ovate, base subrounded to attenuate, apex acute, shortly apiculate, margin broadly callose-thickened, densely and coarsely pectinate, the marginal trichomes hirsute-glandular ca. 1 mm long, golden-yellowish, curved toward the apex, glabrous on both surfaces, keeled, yellowish-green to olive-green, faintly 3(–5)-nerved, only the central vein conspicuous, sparingly beset abaxially with appressed trichomes. Flowers 8-merous, rarely 7- or 9-merous, solitary, terminal, sessile. Bracts 4–6, subsessile, 7–8 × 4–5 mm, ovate, attenuate at the apex, margins callosepectinate, sparsely covered with sessile glands at the base on both surfaces, otherwise similar to the principal leaves; each flower also subtended by 4–6 oblong bracteoles 5 × 2.5 mm (excluding marginal trichomes). Hypanthium (at anthesis) 5–8 mm long, ca. 8 mm wide distally, broadly campanulate, moderately to densely beset with spreading gland-tipped trichomes 1 mm long. Calyx tube ca. 1.5 mm long; calyx lobes (at anthesis) 3–5 × 3–5 mm, membranaceous to chartaceous, ovate to obovate or suborbicular, shortly mucronulate at the apex, margins broadly and conspicuously callose-thickened (0.7 mm wide), ciliate to pectinate or fimbriate-laciniate, the basal marginal cilia glandular, yellowish-green to purple, slightly keeled, glabrous on both surfaces but commonly with

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MARTINS & ALMEDA inconspicuous scattered sessile elongated glands toward the adaxial base near the torus, tardily caducous. Petals 15–25 × 10–15 mm, rose-pink but becoming purple when dry, lacking a distinct white patch at the base, obovate to spatulate, apex oblique-truncate and shortly apiculate or occasionally emarginate, base attenuate to subunguiculate, margin entire, minutely glandular-ciliolate. Stamens 16 (rarely 14 or 18), dimorphic: large (antesepalous) stamens 8 (rarely 7 or 9), filaments 10 mm long, anther thecae 3.5 × 0.6 mm, linear-oblong, yellow abaxially and often turning brown adaxially toward the distal end, rostrum ca. 0.4 mm long, pale yellow, pedoconnective ca. 5 mm long, appendage 1.5 mm long, obscurely bilobed, yellow; small (antepetalous) stamens 8 (rarely 7 or 9), filaments 8 mm long, anther thecae 3 × 0.5 mm, linear-oblong, yellow turning brown, rostrum ca. 0.4 mm long, pedoconnective 2 mm long, appendage 1.5 mm long, rounded to obscurely bilobed, yellow. Ovary 6-locular, 4/5 inferior, style 8–9 mm long, somewhat thickened below the stigma, glabrous, stigma punctiform. Fruiting hypanthium (including calyx lobes) 1.3–1.5 × 6–8 mm, constricted apically above the capsule. Capsule (at maturity) 6–7 mm long, subglobose, coriaceous, brown, enveloped by the persistent hypanthium, dehiscing from the base to the apex. Seeds 0.87–1.39 × 0.47–0.64 mm, oblong, orangish-red to dark brown, periclinal cell walls of the testa concave (foveolate), raphal zone about 50–70% the length of the seed. Chromosome number unknown.

Illustration:— Figure 58 .

Photographic images:— Figures 5D–F .

Phenology:—Flowering January through March and August through December; fruiting intermittently from August through February, and April.

Distribution and habitat:—Endemic to Minas Gerais where it is known only from Serra do Cipó and Parque Estadual Pico do Itambé in damp sites in campo rupestre, campo limpo, sandstone outcrops, and sandy campo along river banks at 1260–1500 m. Figure 20 .

Conservation status:—This species is known from fewer than 30 collections representing about four or five isolated populations of varying size. Most of the collections were made on Serra do Cipó where the species is afforded some protection in Parque Nacional Serra do Cipó. At least one other population is also protected in Parque Estadual Pico do Itambé. The EOO is 8 km ² and the AOO is 8 km ². Based on its few known localities, limited elevational distribution, and periodic threat of habitat degradation by fires we assign a classification of Critically Endangered (CR): B2ab(iii).

Discussion:— Lavoisiera sampaioana has essentially glabrous imbricate leaves with conspicuously callose-thickened pectinate margins, prevailingly 8-merous (rarely 7- or 9-merous) flowers, calyx lobes with broad thickened pectinate-laciniate margins, pink petals, and a 6-locular ovary. In foliar details, petal color, and ovary locule number it is most similar to and probably derived from the larger-leaved forms of the variable and widespread L. imbricata . The calyx details and typically 8-merous flowers present an unmistakable combination of characters not seen elsewhere in the genus. Vidal s.n. (R-166824) is a mixed collection. The two branches mounted on the left-hand side of the sheet are L. sampaioana . The shorter branch on the right-hand side of the sheet is L. confertiflora . Aside from this apparent example of sympatry we know of no other species of Lavoisiera that grow adjacent to L. sampaioana in its comparatively limited area of distribution on the Serra do Cipó. On Pico do Itambé, we have also found L. sampaioana and L. imbricata growing in close proximity in open grassy areas adjacent to campo rupestre.

Additional specimens examined:— MINAS GERAIS: Mpio. Santana do Riacho, Serra do Cipó, about 23–24 km from the bridge over the Rio Cipó on the road from Serra do Cipó (formerly Cardeal Mota), about 38 km S of Conceição do Mato Dentro on a temporary detour road while the main Serra do Cipó / Conceição road was being paved, 19˚14’49.3” S, 43˚30’42.7” W, Almeda et al. 9198 ( CAS!, UEC!) ; Mpio. Santo Antônio do Itambé , Parque Estadual do Pico do Itambé, -18.39868, -43.34816, Almeda et al. 9673 ( BHCB!, CAS!, NY!, RB!, UEC!) ; Mpio. Santo Antônio do Itambé , Parque Estadual do Pico do Itambé, Aranha et al. 161, 163 ( UEC!) : Mpio. Santana do Riacho , Serra do Cipó , Badini 3827 ( US!); Mpio. Santana do Riacho , Serra do Cipó, Badini & Mello Barreto 3403 ( R!) ; Mpio. Santana do Riacho , Serra do Cipó. Estrada MG 010 , ca. 400 m antes da bifurcação entre o Morro do Pilar e Conceição do Mato Dentro, W da Rodovia , M. Campos & Arcanjo CFSC 13584 ( SPF!) ; Mpio. Santana do Riacho , Serra do Cipó , Duarte 9102 ( NY!, RB!, US-2!); Mpio. Santana do Riacho , Vacaria , summit of Serra do Cipó , Km 145 (ca. 170 km N of Belo Horizonte), Irwin et al. 20638 ( F!, MO!, NY!, RB!, US!); Mpio. Santana do Riacho , Km 142 ao longo da Rodovia Lagoa Santa-Conceição do Mato Dentro-Diamantina , Joly & Semir 3192 ( UEC!) ; Mpio. Santana do Riacho , Serra do Cipó , Km 134, estrada do Pilar, Mello Barreto s.n. ( RB!) ; Mpio. Santana do Riacho , Serra do Cipó , Km 134-estrada do Pilar, Mello Barreto 309 ( BHCB ex BHMH!, F!, NY!) ;

LAVOISIERA ( MELASTOMATACEAE )

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MARTINS & ALMEDA

Mpio. Santana do Riacho, Serra do Cipó, Km 140, estrada do Pilar, Mello Barreto 313 (BHCB!, F!, NY!, SP!); Mpio. Santana do Riacho, Serra do Cipó, Km 143, estrada do Pilar, Mello Barreto 1318 (BHCB!, F!, RB!); Mpio. Santana do Riacho, Serra do Cipó, Km 143, estrada do Pilar, Mello Barreto 7046 (BHCB!, BHCB ex BHMH!, F!, NY!); Mpio. Santana do Riacho, Serra do Cipó, Km 138, estrada do Pilar, Mello Barreto 8913 (BHCB!, F!, NY!, SPF!); Mpio. Santana do Riacho, Serra do Cipó, Mello Barreto 8953 (BHCB!, NY!); Mpio. Santana do Riacho, Serra do Cipó, Km 138, estrada do Pilar, Mello Barreto 8964 (BHCB!, F!, IAC!, NY!); Mpio. Santana do Riacho, Serra do Cipó, Km 140, estrada do Pilar, Mello Barreto 9690 (NY!, RB!); Mpio. Santana do Riacho, Serra do Cipó, próximo a sede do IBAMA do Alto do Palácio, Pirani et al. CFSC 11914 (CAS!, SPF!); Mpio. Santana do Riacho, Serra do Cipó, Fazenda da Cachoeira Capivara, Sakuragui et al. 116 (ESA!, UEC!); Mpio. Santana do Riacho, Km 139 (antigo 142) ao longo da Rodovia Lagoa Santa-Conceição do Mato Dentro-Diamantina, Semir & A. M. Joly 3789 (SP!, UEC!); Mpio. Santana do Riacho, Serra do Cipó, Km 136, Semir 8657 (IAC, UEC!); Mpio. Santana do Riacho, Serra do Cipó, Rod. Belo Horizonte-Conceição do Mato Dentro, próx. ao trevo para Morro do Pilar, V. C. Souza & Sakuragui et al. 1966 (ESA!, UEC!); Mpio. Diamantina , estrada para Araçuaí, ca. 2 km de Diamantina, Souza et al. 28344 (ESA!, UEC!); Mpio. Santana do Riacho, Serra do Cipó, Vidal s.n. (R!); Mpio. Santana do Riacho, Serra do Cipó, entre Posto Palácio e Morro do Pilar, Vidal II-6063 (R!); Mpio. Santana do Riacho, Serra do Cipó, estrada Lagoa Santa-Conceição do Mato Dentro, Km 126, Fazenda Cachoeira da Capivara, Alto do Paraíso, Wendt et al. 102 (RB!).

Figures

FIGURE 5. Images of Lavoisiera species. A−C. L. rundeliana (Almeda et al. 9667). D, F. L. sampaioana (unvouchered images). E. L. sampaioana (Almeda et al. 9198). G−H. L. senae (Almeda et al. 9186). I. L. subulata (Almeda et al. 8571). J. L. tetragona (Almeda et al. 7808). K−L. L. vestita (Aranha et al. 164). Image credits: A−C, E, G−J. Frank Almeda; D, F. Ernesto Lemes; K, L. Gustavo Shimizu.

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

FIGURE 58. Lavoisiera sampaioana. A. Habit. B. Adaxial bracteole surface. C. Flower. D. Hypanthium, calyx lobes and ovary apex with enlargement of adaxial calyx lobe surface below the sinuses (above right). E. Petal with enlargement of margin detail (above). F. Ventral view of antesepalous stamen. G. Ventral view of antepetalous stamen. H. Ovary cross-section. I. Seed. (Based on: A–I, Semir & Joly 3789, UEC.)