Lavoisiera alba Martius & Schrank ex Candolle (1828: 103–104)

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

2. Lavoisiera alba Martius & Schrank ex Candolle (1828: 103–104) . Type :— BRAZIL. Minas Gerais: “In alpinis apricis tam petrosis siccis quam irriguis inter Villam Riccam et Tejuco,” C. F . P. Martius s.n. (holotype: M-0174610- n.v., online image!, photos: F!, NY!; isotypes: BM!, G-DC-n.v., online image!, M) .

Erect, openly branched subshrubs or arching shrubs (0.5–)1(–2) m tall, glabrous throughout. Branches and branchlets quadrangular, prominently angled and carinate to narrowly winged, slightly furrowed longitudinally on opposite faces, somewhat compressed distally, frequently leafy to the base, occasionally defoliating basally; internodes (5–)8–15(–25) mm long, knobby thickenings almost inconspicuous, nodes minutely glandular-puberulous, leaf scars inconspicuous. Leaves sessile, semi-amplexicaul, spreading to subimbricate on the branchlets distally; blade 20–60 × 10–30(–40) mm, firmly chartaceous to subcoriaceous, essentially flat, broadly elliptic to oblong-elliptic, occasionally lanceolate or rarely ovate, base rounded to subcordate, apex obtuse to broadly acute, shortly apiculate or mucronulate, margins entire and subcallose, pale green or bluish-green, glaucous and glabrous but sometimes flushed with red, 5–7(–9)-nerved (only the second pair from the margin extending to the apex), with laxly reticulate inconspicuous venules evident on the abaxial surface. Flowers 5-merous, in simple

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(rarely compound) dichasia, sometimes reduced to paired or solitary flowers, at first terminal but eventually becoming pseudoaxillary by elongation of lateral shoots, the central flower of each dichasium sessile or subsessile with pedicels 13 mm long, lateral (uppermost) flowers on each simple dichasium with pedicels 2–4(–5) mm long. Bracts 30–40 × 20–25 mm, concave-involucrate, green, lateral (uppermost) flowers of each dichasium subtended by a pair of sessile bracteoles 19–22 × 8–10 mm, that are similar to the principal leaves but somewhat concave-involucrate and enveloping buds prior to anthesis, bracteole blade elliptic-lanceolate, base rounded, apex acute to mucronulate, obscurely 5-nerved. Hypanthium (at anthesis) 8–10 mm long, narrowly campanulate, 2.5 × 4.5 mm wide at the apex, constricted above the ovary, glabrous but sometimes minutely granulose-verruculose, pale green. Calyx tube inconspicuous, up to ca. 1 mm long; calyx lobes (at anthesis) 3.5–4 × 3–4 mm, chartaceous, broadly triangular, acute to mucronulate at the apex ending with a spiny trichome 0.5–1.5 mm long, margins subcallose, persistent, pale green and glabrous on both surfaces. Petals 15 – 22 × 9–10 mm, (falling away together with stamens as a unit after anthesis), white and sometimes with a yellow base, elliptic to obovate, apex asymmetrically rounded to truncate or emarginate, base attenuate, margin entire or minutely glandular-ciliolate. Stamens 10, dimorphic: large (antesepalous) stamens 5, filaments 6–7 mm long, pale yellow, anther thecae 5.5 × 1.5 mm, dark yellow turning brown, oblong, rostrum 0.5 mm long, pedoconnective 6–7 mm long, appendage 11.5 mm long, rounded to emarginate or obscurely bilobed, yellow; small (antepetalous) stamens 5, filaments 5 mm long, pale yellow, anther thecae 4.5 × 1.5 mm, dark yellow turning brown, oblong, rostrum ca. 0.5 mm long, pedoconnective 2–2.5 mm long, appendage 0.5 mm long, shallowly bilobed to rounded, yellow. Ovary 5-locular, 4/5 inferior, style 15 mm long, slightly curved apically, pale yellow, glabrous, stigma punctiform. Fruiting hypanthium (including calyx lobes) 13–20 mm long, oblong, constricted distally above the ovary summit but below the calyx lobes. Capsule (at maturity) 7–8 × 4–4.5 mm, globose to oblong, enveloped by the persistent hypanthium and calyx lobes, dehiscing from the base to the apex. Seeds 0.63–0.70 × 0.27–0.41 mm, oblong to reniform or subcochleate, reddish-brown, periclinal cell walls of the testa concave (foveolate), the raphal zone ± obliquely truncate on micropylar end of the seed. Chromosome number unknown.

Illustrations:— Figure 17 ; Martius 1831: t. 268.

Photographic images:— Figures 1B, C ; 6A, B .

Phenology:—Flowering from January through July, and in September and October; fruiting in February, and April (young) through July (old).

Distribution and habitat:—Largely centered in Minas Gerais on the Serra do Espinhaço from the Ouro Preto region north to Serra do Cipó, Serra do Cabral, and the Diamantina plateau with one known population from Bahia. Local in grassy meadows and adjacent sandy campo, rocky sandstone hilltops with wet spots, cerrado rochoso, brejo, gallery forest margins, campo rupestre, and stream banks at 1000–1400(–1800) m elev. Figure 18.

Conservation status:— We have examined over 65 collections of this species representing several populations from its comparatively widespread range in Minas Gerais and Bahia. The EOO is 5,466 km ² and the AOO is 28 km ². At least two populations appear to be afforded some protection, one in Parque Estadual do Biribiri and one in Parque Estadual da Serra do Cabral. We recommend a classification of Vulnerable (VU): B2ab(iii).

Discussion:— Lavoisiera alba is unusual among congeners in having quadrangular upper branchlets that are conspicuously angled and carinate to narrowly winged. Other diagnostic characters include its overall glabrosity, bluish-green or pale green glaucous leaves ( Figure 1B ) that lack glandular punctations on both surfaces, 5-merous, pedicellate (2–5 mm) flowers, uniformly white petals, persistent calyx lobes, and a 5-locular ovary. The label of Anderson 35372 reports that the flowers of this species are fragrant. We have not observed floral fragrance in flowers of this species during our field studies. If verified, this would evidently be the only species in the genus with floral scent.

Among the species of Lavoisiera with 5-merous flowers and a 5-locular ovary only L. gentianoides is consistently white-flowered. It differs from L. alba in having non-glaucous leaf blades that are lanceolate to oblong-lanceolate with the adaxial surface sometimes finely setulose (the trichomes 1 mm long) and the abaxial surface glabrous and inconspicuously but distinctly punctate. In L. gentianoides the inflorescence and hypanthia differ as well. It has congested dichasia of 6–10 sessile flowers in a glomerulate head, the hypanthia and calyx lobes are beset with spreading gland-tipped trichomes, and the calyx lobes are tardily caducous in post-anthesis.

For a comparison of Lavoisiera alba with other glaucous-leaved species, see the discussion under L. cordata .

LAVOISIERA ( MELASTOMATACEAE )

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Additional specimens examined:— BAHIA: Mpio. Abaíra, Catolés, 13°20'S, 41°53'W, Ganev 366 (CAS!, HUEFS!). MINAS GERAIS: Mpio. Ouro Preto, estrada Real about 23 km SW of Ouro Preto, 20°28'S, 43°35'W, Almeda et al. 8388 (CAS!, MO!, UEC!); Mpio. Diamantina, Cachoeira Sentinela off of the road to Biribiri, 18°10'S, 43°37'W, Almeda et al. 8476 (CAS!, NY!, UEC!); Diamantina plateau about 17 km west of Hwy. BR 259 just south of Guinda on the road to Conselheiro Mata , 18˚18.095’S, 43˚49.336’W, Almeda et al. 8992 (BHCB!, CAS!, COL!, UEC!); Mpio. Diamantina , road from Diamantina to Mendanha at Km 585 and the Caminho dos Escravos, 18°21751’S, 43°59379’W, Almeda et al. 9557 (BHCB!, CAS!, K!, NY!, RB!, UEC!); Mpio. Diamantina ,

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18 km W of Hwy MG 220 along road to Conselheiro Mata , 18°30142’S, 43°82372’W, Almeda et al. 9624 (BHCB!, CAS!, NY!, UEC!); Serra do Espinhaço, ca. 35 km SW of Gouveia, Km 243 on MG 259, Anderson et al. 35080 (COL!, F!, MICH!, MO!, NY!); Serra do Espinhaço, ca. 8 km N of Gouveia on road to Diamantina, Anderson et al. 35372 (F!, NY!, US!); Mpio. Diamantina , estrada para Conselheiro Mata, Km 173.5, Atui et al. 52 (CAS!); Barboza s.n. (R!); Mpio. Diamantina, Conselheiro Mata, Brade 13723 (BHCB ex BHMH!, NY!, RB!); Mpio. Gouveia, Fazenda Contagem, Chukr et al. CFCR 9564 (CAS!, SPF!, UEC!); without exact locality, Claussen 38 (P!); without exact locality, Claussen s.n. (NY!); without exact locality, Claussen 116 (G!); Mpio. Diamantina , estrada Diamantina-Conselheiro Mata, Km 174, Cordeiro et al. CFCR 9456 (CAS!, SPF!, US!); Mpio. Ouro Preto, Saramanto, Damazio 1483 (G!); Mpio. Ouro Preto, between Itabirito and junction with Belo Horizonte road, at km 16, Davis & Shepherd D59658 (UEC!); Mpio. Belo Horizonte, Pico da Serra do Curral, Ducke herb. 21655 (RB!); Mpio. Belo Horizonte, Pico da Serra; Horto Oswaldo Cruz, Gehrt s.n. (CAS!); Mpio. Diamantina , 20 km S de Diamantina . Serra na estrada para Conselheiro Mata, Gibbs 5253 (UEC!); Serra de Ouro Branco, Glaziou 14760 (G!, K!, LE!, P!, R!, S!); Mpio. Santana do Riacho, Serra do Cipó, Glaziou 19272 (C!, K!, R!); Glaziou 19275 (C!, G!); Mpio. Ouro Preto, estrada para Rodrigo Silva (variante da Estrada Ouro Preto-Ouro Branco), 20°26’50”S,

LAVOISIERA ( MELASTOMATACEAE )

Phytotaxa 315 (1) © 2017 Magnolia Press • 47 43°34’40”W, Goldenberg et al. 1516 (NY!, UPCB); Mpio. Ouro Preto, Gomes 609 (R!); Mpio. Diamantina, Rodovia Guinda-Conselheiro Mata, Hatschbach & Zelma 49709 (MBM!); Mpio. Gouveia, BR 359, Serra do Espinhaço, Hatschbach et al. 36428 (COL!, US!); Mpio. Gouveia, Serra do Espinhaço, Hatschbach 27282 (C!, COL!, MBM!, NY!, S!, US!); Mpio. Diamantina, Rodovia Guinda-Conselheiro Mata, Km 17, Hatschbach 44714 (COL!, F!, US!); Curimataí, Rio Preto (Mun. Buenópolis), Hatschbach et al. 73646 (MBM!); Serra do Ouro Branco, Hoehne 5195 (NY!); Serra de Itabirito , ca. 45 km SE of Belo Horizonte, Irwin et al. 19695 (NY!); ca. 28 km SW of Diamantina on road to Gouveia, Irwin et al. 22025 (B!, NY!, S!); ca. 20 km SW of Diamantina, Irwin et al. 22505 (F!, LE!, MO!, NY!, RB!, US!); Mpio. Ouro Preto, estrada Ouro Preto-Mariana, H. C. de Lima et al. 1511 (RB!); Serra de Itabira, Lund s.n. (C!, US!); 20–30 km S of Gouveia, on road between Diamantina and Curvelo, Maguire et al. 49195 (NY!, RB!); C. F. P. Martius s.n. (M!); C. F. P. Martius 920 (BM!, G-2!, K-2!, LE- 2!, MO!, NY!, W-2!); Mpio. Diamantina , estrada para Conselheiro Mata, Km 174, Mayo et al. CFCR 10416 (SPF!, US!); Mpio. Belo Horizonte, Serra do Curral, Mello Barreto 197 (F!); Mpio. Belo Horizonte, Serra do Curral, Mello Barreto 9692 (R!); Serra do Rola Moça, divisas de Betim e Brumadinho, Mello Barreto 10628 (BHCB ex BHMH!); Gandarela, Mello Filho, L. Emygdio et al. 3320 (NY!, R!); Mpio. Diamantina , estrada para Conselheiro Mata (MG 220), 19.1 km da Rodovia BR 367 (Gouveia-Araçuaí), Mello-Silva et al. 1152 (CAS!); Estrada Diamantina-Conselheiro Mata, Occhioni 5572 (F!, US!); Mpio. Diamantina, Pereira 1573 (F!, K!, RB!, US!); Mpio. Diamantina, Agua Fria, Pereira & Pabst 2817 (B!, F!, K!, RB!); Serra do Ouro Branco, Pereira 2946 (RB!); Mpio. Diamantina , estrada para Biribiri, perto da Sentinela, 18°10'S, 43°37'W, Pirani et al. 4028 (CAS!, SPF!); Mpio. Santana do Riacho, Santana do Pirapama, Fazenda Inhame ( Serra Mineira ) Serra do Cipó, 18°55'S, 43°54'W, Pirani et al. CFSC 8115 (SP!, SPF!, UEC!); Ouro Branco, Pohl s.n. (BM!); Serra do Cabral, Augusto de Lima, Casa da Mina , 18°02’54”S, 44°19’52”W, Rodrigues et al. 76 (UEC!); Serra Ouro Branco, Saint-Hilaire 251 (P!); Mpio. Diamantina, Serra dos Cristaes, Schwacke 7805 (RB!); Ouro Preto, Schwacke 9344 (BHCB!); Mpio. Diamantina , estrada Diamantina-Conselheiro Mata , ca. 19 km da estrada Diamantina-Gouveia, 18°18'S, 43°49'W, V. C. Souza & J. P. Souza 22259 (CAS!); Mpio. Ouro Branco, estrada velha entre Ouro Branco e Ouro Preto, ca. 7 km de Ouro Branco, 20°30'S, 43°38'W, V. C. Souza et al. 8018 (CAS!, ESA!, SPF!, UEC!); Mpio. Ouro Preto, estrada velha Ouro Branco-Ouro Preto, ca. 15 km de Ouro Branco, 20°28'S, 43°35'W, V. C. Souza et al. 8051 (ESA-2!); Mpio. Santana do Riacho, Serra do Cipó, Strang 64 (R!); Mpio. Ouro Preto, Morros perto da cidade, Ule 2533 (R!); Mpio. Lagoa Santa, Warming s.n. (C!, S!); Warming 2746 (C!); Mpio. Lagoa Santa, Warming 2747 (C!); Mpio. Nova Lima, Serra da Mutuca , near Belo Horizonte, Williams & Assis 6705 (NY!, US!). MINAS GERAIS?: Pohl 3683 (W!); Warming s.n. (W!).

Figures

FIGURE 1. Images of Lavoisiera species. A. L. adamantium (Almeda et al. 8504). B–C. L. alba (Almeda et al. 9624). D–E. L. arachnoidea (unvouchered image). F. L. belinelloi (Almeda et al. 8532). G. L. bradeana (Almeda et al. 9718). H. L. canastrensis (Almeda et al. 7878). I. L. caryophyllea (Almeda et al. 9172). J–K. L. chamaepitys (Almeda et al. 8500). L. L. confertiflora (Almeda et al. 9725). Image credits: A–C, F–L. Frank Almeda; D–E. Karina Fidanza.

FIGURE 6. SEM images of seeds for representative Lavoisiera species showing lateral symmetrical plane (left) and detail of testa cells and cell wall microrelief (right). A−B. L. alba (Hatschbach 27282). C−D. L. caryophyllea (Tamashiro 25639). E−F. L. chamaepitys (Markgraf et al. 3437). Scale bars: A=150 µm, B=38 µm; C=380 µm, D=38 µm; E=231 µm, F=10 µm.

FIGURE 17. Lavoisiera alba. A. Habit. B. Adaxial leaf surface. C. Bud and subtending bracts. D. Flower. E. Hypanthium and calyx lobes. F. Ovary cross-section. G. Petal with enlarged margin detail (lower right). H. Ventral view of antesepalous stamen. I. Ventral view of antepetalous stamen. J. Seed. (Based on: A–J, Almeda et al. 8388, CAS, UEC.)