Lavoisiera macrocarpa Naudin (1844: 148)

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

23. Lavoisiera macrocarpa Naudin (1844: 148) . Lavoisiera pulcherrima Martius & Schrank ex Candolle var. macrocarpa (Naudin) Barreto (1935b: 190) . Type:— BRAZIL. Minas Gerais: “In rupibus montium vulgo Serra do Frio ( Diamantina ), Minas Geraes,” mai, A.-C. Vauthier 16 (holotype: P!; isotype: G!, P-00723525-n.v., online image!).

= Lavoisiera selloana Cogniaux in Martius (1883: 152). syn. nov. Type :— BRAZIL. Minas Gerais: Serra de Santo Antônio, H. L. Sello 1743 (holotype: B, destroyed, photos: F!, NY!; lectotype, here designated: K!; photo: F!).

= Lavoisiera gouveana Barreto (1935a: 10) . syn. nov. Type :— BRAZIL. Minas Gerais: “Habitat in civitatae Minas Geraes, in campis siccis arenosisque in Serra do Cipó secus margines viae ad vicum Morro do Pilar ubi rara,” H. L . Mello Barreto 9682 (holotype: R!) .

Erect, open divaricately and dichotomously branched shrubs to 0.4–1.5(–2) m tall, essentially glabrous, rarely with entire non-fertile branches or basal leaves sparsely to moderately glandular-hirsute, the trichomes ca. 1 mm long. Branches and branchlets rounded to subrounded or subquadrangular, slightly furrowed longitudinally on opposite faces, leaves often congested at the ends of branchlets, defoliating and decorticating basally with age; internodes (2–)4–6(–10) mm long, with knobby thickenings that persist where a leaf has fallen away, nodes with few and inconspicuous glandular-puberulous trichomes. Leaves sessile, semi-amplexicaul, widely to retrorsely spreading, somewhat imbricate and erect on growing shoot tips, rarely dimorphic with respect to pubescence on a single plant or branch, the pubescent leaves membranaceous, sparsely glandular-hirsute on both surfaces, the glabrous leaves

LAVOISIERA ( MELASTOMATACEAE )

Phytotaxa 315 (1) © 2017 Magnolia Press • 121 blue-green (sometimes flushed with maroon) and glaucous adaxially, semi-succulent when fresh but coriaceous when dry; blade 10–30(–40) × 7–17(–25) mm, oblong-elliptic to ovate, both surfaces of some leaves of some specimens drying with an irregular mottled pattern of lighter or darker green or brown bands or patches of varying sizes, base subrounded to attenuate, apex obtuse to broadly acute, sometimes shortly mucronulate, margins entire and subcallose on the glabrous leaves but shortly subserrulate and glandular-ciliate on the pubescent leaves, flat, 3(–5–7)-nerved, only the midvein elevated and conspicuous. Flowers prevailingly 8-merous but occasionally 9–10-merous, rarely 7-merous, shortly pedicellate, solitary or in clustered simple dichasia, rarely paired, at first terminal but becoming central by the elongation of lateral branches. Bracts or the uppermost paired leaves subtending the flowers becoming wider and longer (35 × 25 mm) than the principal leaves, frequently flushed pink, enveloping and initially concealing the buds. Hypanthium (at anthesis) 8–9 × 4 mm (8 mm wide distally), campanulate, glabrous and somewhat granulose, green. Calyx tube ca. 1 mm long; calyx lobes (at anthesis) 3–4 × 3 mm, chartaceous, triangular, narrowly rounded at the apex with a terminal pungent trichome, margins entire, callose, glabrous on both surfaces, persistent. Petals 28–35(–45) × 15–18(–30) mm (adherent at the very base and falling away together with stamens as a unit after anthesis), dark pink or magenta, with a short greenish-white band at the base, obovate to spatulate, apex emarginate or obtuse-apiculate, varying to bluntly lacerate and shortly glandular-ciliolate, base attenuate to unguiculate, margin minutely glandular-ciliate. Stamens 12, 14, or 16 (rarely 20), dimorphic: large (antesepalous) stamens (6–7–)8(–10), filaments 9–11 mm long, yellow, anther thecae 5–6 × 1.5–2 mm, oblong, pink, pink-orange, or reddish turning buff or brownish, rostrum ca. 1.2 mm long, yellowish-white, pedoconnective 6–7 mm long, appendage ca. 2 mm long, rounded-triangular, yellow; small (antepetalous) stamens (6 –7–)8(–10), filaments 7–8 mm long, yellow, anther thecae 4– 5 × 1.5–2 mm, yellow, oblong, rostrum ca. 1 mm long, pedoconnective ca. 3–4 mm long, appendage 1–1.5 mm long, rounded to somewhat bilobed when dry, yellow. Ovary (7–)8-locular, 4/5 inferior, style ca. 10 mm long, declinate, glabrous, yellow, stigma punctiform. Fruiting hypanthium (including calyx lobes) 10–15 × 10–11 mm, constricted distally, pedicels 1 mm long. Capsule (at maturity) 10–15 mm long, globose, coriaceous, enveloped by the hypanthium and calyx lobes, dehiscing from the apex to the base, the vascular strands persisting long after capsule walls have fallen away. Seeds 0.98–1.19 × 0.53–0.58 mm, narrowly oblong, yellowish brown becoming dark grayish-brown, periclinal cell walls of the testa concave (foveolate), raphal zone about 40% the length of the seed. Chromosome number unknown.

Illustration:— Figure 46 .

Photographic images:— Figures 3L ; 4A–C .

Phenology:—Flowering from February through May and August through December; fruiting January through April and August through December.

Distribution and habitat:—Endemic to Minas Gerais where it is largely centered on the Serra do Cipó region of the Cadeia do Espinhaço; one collection has been made near Caeté to the south (just east of Belo Horizonte) and other collections were made as far north as the municípios of Diamantina and Congonhas do Norte. It grows in campo rupestre, campo graminoso, open fields with quartzite outcrops, and rocky creek margins at 1180–1380 m. Figure 39 .

Conservation status:—This species is known to us from just under 50 collections that were made over several decades. A majority of these, however, come from a population centered in the município of Santana do Riacho on the Serra do Cipó. The EOO is 484 km ² and the AOO is 32 km ². A large part of the population at this latter locality is located within Parque Nacional Serra do Cipó. Despite official protection this area does experience periodic drought and fires. In view of its limited AOO and narrow elevational distribution we recommend a classification of Endangered (EN): B2ab(iii).

Discussion:— Lavoisiera macrocarpa has large showy intense pink flowers that can measure nearly 10 cm across when fresh. Few other campo rupestre shrubs on the Serra do Cipó are as spectacular during the Brazilian spring and fall seasons. The flowers of this species are prevailingly 8-merous with an 8-locular ovary but extreme variants can have flowers that are 6–7-merous or occasionally 10-merous. The large flowers coupled with conspicuously veined petals and the open, divaricately branched habit are unmistakable in the genus. Cogniaux (1883) erroneously described the leaves of L. macrocarpa as 1-nerved but he correctly noted that the capsules are apically dehiscent. Its leaves are in fact 3–7-nerved but sometimes only the midvein is elevated and conspicuous.

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MARTINS & ALMEDA

An unusual feature of L. macrocarpa that is shared with the Serra da Lapinha (Minas Gerais) population of L. cordata is the coloration of adaxial leaf surfaces. Upon drying, the upper leaf surfaces of some specimens (but not all specimens or all leaves on any one specimen) exhibit an irregular mottled pattern of lighter and darker green bands or patches. In specimens evidently subjected to more intense heat on drying the coloration appears as darker tan and brown mottling. In some leaves the lighter coloration is more or less concentrated near or restricted to an area adjacent to the midvein. In our field experience, this foliar color patterning is never evident in fresh material but its presence in dried material is distinctive and appears to be diagnostic for these species. Field study has also

LAVOISIERA ( MELASTOMATACEAE )

Phytotaxa 315 (1) © 2017 Magnolia Press • 123 led to the discovery of another extraordinary characteristic. The large petals appear to be adherent at the very base for a short distance (ca. 0.25 mm). Consequently, the petals do not fall away individually following anthesis. Instead, the petals all close to envelop the androecium and the entire complement of petals and stamens (but not the style) fall away as a unit following pollination.

Aside from the commonly encountered variation in leaf size of plants between and within populations, the only notable variation exhibited by L. macrocarpa involves the indumentum of upper cauline internodes and principal leaves. Before we studied this species in the field, we were puzzled by a few herbarium specimens that consisted of branches with pubescent leaves and internodes mounted alongside branches and leaves that were completely glabrous. Because the two different morphs never seemed to be fertile on the same specimen, we were hard-pressed to determine whether we were dealing with a mixed collection or unusual variation. Field study of a population on Serra do Cipó (Almeda et al. 8579) allowed us to resolve this mystery. In one population of L. macrocarpa we observed individual plants with entirely sterile branches that had pubescent internodes and leaves, together with fertile branches that had leaves and internodes that were completely glabrous. On other individuals we discovered that the basal leaves on a branch were copiously pubescent whereas the uppermost leaves on the same branch closer to the flowers were completely glabrous. On other branches we discovered that the basal leaves were glabrous and newer growth exhibited copiously pubescent leaves and internodes. This apparent age-related change in indumentum production is unusual even for Lavoisiera . We have seen this phenomenon to a lesser extent in L. crassifolia and L. firmula and in Microlicia wurdackiana Almeda & A.B. Martins (2012: 468–470) but never in the hundreds of other species of Melastomataceae that we have had the opportunity to study in the field.

Cogniaux (1883), who did not study Lavoisiera in the field, described L. selloana from a single collection that has the pubescent leaves described above and 6–7-merous flowers. We interpret the type of L. selloana to be an extreme and uncommon variant of L. macrocarpa and see no merit in continuing to recognize it at any taxonomic level. The type specimen of L. gouveana , the other species here relegated to the synonymy of L. macrocarpa , has 7–8-merous flowers and branches with pubescent basal leaves and uppermost glabrous leaves like those we observed in the field. Again, these purported differences fall within the range of variation here attributed to L. macrocarpa .

Many collections of L. macrocarpa in herbaria have been identified as Lavoisiera pulcherrima Martius & Schrank ex Candolle var. latifolia Cogn. and L. pulcherrima var. ovalifolia Barreto. These two varieties were published by Cogniaux (1883) and Mello Barreto (1935b) respectively. The latter and several other varieties were not validly published by Mello Barreto according to Art. 36 of the I.C.N. (McNeill et al. 2012) because they lacked a Latin diagnosis or description. If Barreto’s proposed varieties were validly published they would be reduced to synonymy because they have no diagnostic features warranting formal recognition.

The flowers on some herbarium specimens of L. macrocarpa have stamens that have been chewed and robbed of pollen. In a population on Serra do Cipó (Almeda et al. 8545), we observed large beetles ( Conognatha (Pithiscus) vulnerata – Buprestidae : Buprestinae , tribe Stigmoderini ) feeding on and essentially destroying anthers of numerous flowers on several individuals. Trigona bees are known to be dystrophic stamen feeders for many neotropical Melastomataceae ( Almeda 1977; Renner, 1983) but to our knowledge no beetles have been reported to feed on melastome stamens. This destructive feeding behavior by buprestid beetles must lead to considerable reproductive loss because ravaged anthers cannot be serviced by legitimate pollinators that employ the effective buzz method of pollen extraction from poricidal anthers.

The closest relative of L. macrocarpa appears to be L. pulcherrima . For a comparison of these two species, see the discussion under the latter. Another species that is superficially similar to L. macrocarpa is L. cordata . Both are shrubs with open lax or divaricate branching and leaf blades of similar size and shape that are glaucous and blue-green and sometimes flushed with purple or maroon especially on the young leaves. Lavoisiersa cordata differs most notably in having prevailingly 6–7-merous flowers, consistently creamy white petals (sometimes with a yellow flush) with conspicuous translucent venation ( Figures 2A–C ), pale yellow antesepalous anther thecae that are reddish or pink at the base of the rostra, tardily caducous (vs. persistent) calyx lobes that are glandular-ciliate along the margins ( Figure 32D ), and prevailingly 6-locular ovaries ( Figure 32E ).

Additional specimens examined:— MINAS GERAIS: Mpio. Santana do Riacho, Serra do Cipó, Km 107 along the road from Lagoa Santa to Conceição do Mato Dentro , 19°17'S, 43°35'W, Almeda et al. 8545 ( CAS!, MO!, UEC!); Mpio. Santana do Riacho , Serra do Cipó , 20 km beyond turnoff to Serra Morena off the road from Lagoa Santa to Conceição do Mato Dentro , 19°14'S, 43°30'W, Almeda et al. 8579 ( CAS!, MO!, NY!, UEC!); Mpio. Santana do Riacho , Serra do Cipó , 49 km from Distrito Cardeal Mota along rutted unpaved road to Pico do

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Breu, 19°2'S, 43°42'W, Almeda et al. 8597 (CAS!, UEC!); Serra do Cipó, Mpio. Santana do Riacho, Km 132 on road from Serra do Cipó (formerly Cardeal Mota) to Conceição do Mato Dentro, 19˚15’12.2”S, 43˚32’27.1”W, Almeda et al. 8900 (CAS!, MO!, UEC!); Mpio. Santana do Riacho, Serra do Cipó, about 23 km from the bridge over the Rio Cipó on the road to Conceição do Mato Dentro, 19˚15’34.8”S, 43˚33’10.8”W, Almeda et al. 9173 (BHCB!, CAS!, COL!, MICH!, UEC!); Mpio. Santana do Riacho, Serra do Cipó, Chapéu do Sol, Andrade 2 (BHCB!); Mpio. Santana do Riacho, Serra do Cipó, próximo à estatua do Velho Juquinha, do lado esquerdo da estrada que liga Conceição do Mato Dentro a Belo Horizonte, Benko-Iseppon 288 (CAS!); Mpio. Santana do Riacho, Kms 117–118 (antigo) da Rodovia Belo Horizonte-Conceição do Mato Dentro, Castro-Souza & Menezes CFSC 11590 (SPF!, US!); Mpio. Santana do Riacho, Serra do Cipó, Km 129, Duarte 1988 (NY!); Mpio. Santana do Riacho, Serra do Cipó, Km 129 e 131, Palácio, Duarte 2084 (MO!, NY-3!); Mpio. Santana do Riacho, Serra do Cipó, Duarte 6397 (F!, G!, RB!); Mpio. Santana do Riacho, Serra do Cipó, along road at Km 120, 19°18'S, 43°35'W, Eiten & Eiten 6832 (K!, NY!, UB!, US-2!); Mpio. Congonhas do Norte, estrada Congonhas-Gouveia, a 9 km de Gouveia, 18°46'S, 43°44'W, Furlan et al. CFSC 8332 (SPF!, US!); Mpio. Congonhas do Norte, trilha em direção a Retiro do Barbado, 18°51'S, 43°45'W, Furlan et al. CFSC 8352 (SPF!, US!); Mpio. Santana do Riacho, Serra do Cipó, Giani 6010 (BHCB!, HUFU!); Glaziou 12974 (LE!); Mpio. Diamantina, Serra dos Cristais, Glaziou 19268a (BR!, P!, R!); Mpio. Santana do Riacho, Hatschbach & Koszicki 35353 (C!, M!, MO!, UEC!, US!); Mpio. Santana do Riacho, Serra do Cipó, Heringer 7348 (UB!, US!); Mpio. Santana do Riacho, Km 128 ao long da Rodovia Lagoa Santa-Conceição do Mato Dentro-Diamantina, Joly & Semir 2970 (NY!); Mpio. Santana do Riacho, Km 132 ao long da Rodovia Lagoa Santa-Conceição do Mato Dentro-Diamantina, Joly & Semir 3102 (UEC!); Mpio. Santana do Riacho, Serra do Cipó, Macedo s.n. (NY!, RB!, S-2!, US!); Mpio. Santana do Riacho, Serra do Cipó, 3.5 miles from Hotel Chapéu do Sol, Maguire et al. 44647 (NY!, UB!, US!); Mpio. Santana do Riacho, Serra do Cipó, 3.5 miles from Hotel Chapéu do Sol, Maguire et al. 44664 (G!, NY!, RB!, UB!, US!); Mpio. Santana do Riacho, Serra do Cipó, between Kms 111 and 128, Maguire et al. 44706 (NY!, US!); Mpio. Santana do Riacho, Serra do Cipó, Mansur et al. 16562 (BHCB!); Mpio. Santana do Riacho, Serra do Cipó, Km 131, Mello Barreto 192 (BHCB ex BHMH!); Mpio. Santana do Riacho, Serra do Cipó, Km 131, Mello Barreto 216 (BHCB ex BHMH!); Mpio. Santana do Riacho, Serra do Cipó, Km 136-estrada do Pilar, Mello Barreto 221 (F!, NY!); Mpio. Santana do Riacho, Serra do Cipó, Km 131, Mello Barreto 1314 (M!, NY!); Mpio. Santana do Riacho, Serra do Cipó, Km 121, Mello Barreto 7031 (F!); Mpio. Santana do Riacho, Serra do Cipó, Km 131- Palácio, Mello Barreto 9256 (F!); Mpio. Diamantina, Boa Vista, Mello Barreto 9695 (BHCB!, BHCB ex BHMH!); Mpio. Caeté, Serra Catinga, Mendes Magalhães 2273 (BHCB ex BHMH!, RB!); Mpio. Santana do Riacho, Km 126 da Rodovia Belo Horizonte-Conceição do Mato Dentro, Menezes et al. CFSC 6555 (SPF!, US!); Mpio. Santana do Riacho, Serra do Cipó, Km 130 a 140, Occhioni et al. s.n. ( US!); Mpio. Santana do Riacho, Km 126 ao longo da Rodovia Belo Horizonte-Conceição do Mato Dentro, J. Oliveira et al. CFSC 9065 (NY!, SPF!, UEC!); Mpio. Santana do Riacho, Serra do Cipó, Fazenda Palácio, Palacios et al. 3479 (R!); Mpio. Santana do Riacho, Serra do Cipó, Km 125 da Rodovia Belo Horizonte-Conceição do Mato Dentro. Elevação frente à estátua do Velho Juca, Pirani et al. CFSC 12250 (CAS!, SPF!); Mpio. Santana do Riacho, Serra do Cipó, Km 125 da Rodovia Belo Horizonte-Conceição do Mato Dentro. Elevação atrás da estátua do Velho Juca, Pirani et al. CFSC 12694 (CAS!, SPF!, US!); Mpio. Santana do Riacho, Serra do Cipó, Pilar, Km 137, Sampaio 6576 (R!); Mpio. Santana do Riacho, Serra do Cipó, 6 km north of Palácio, Segadas-Vianna & Lorêdo Jr. 1079 (NY!, R!); Mpio. Santana do Riacho, Serra do Cipó, 6 km north of Palácio, Segadas-Vianna & Lorêdo Jr. 1094 (NY!, R!); Mpio. Santana do Riacho, Km 127 ao longo da Rodovia Lagoa Santa-Conceição do Mato Dentro-Diamantina, Semir & Sazima 4716 (MBM!); Mpio. Santana do Riacho, Serra do Cipó, Semir 8663 (ESA, HUFU, IAC, UEC!); Mpio. Santana do Riacho, Serra do Cipó, Tamashiro 25643 (MBM!, UEC!); Mpio. Santana do Riacho, Serra do Cipó, Travassos s.n. (RB!); Mpio. Serro, Boca da Mata, Williams & Assis 7929 (CAS!, SP).

Figures

FIGURE 2. Images of Lavoisiera species. A. L. cordata (Almeda et al. 7798). B−C. L. cordata (Almeda et al. 9696). D. L. crassifolia (Almeda et al. 8442). E. L. crassifolia (Almeda et al. 7807). F. L. crassifolia (Almeda et al. 9051). G−H. L. firmula (Almeda et al. 9197). I. L. gentianoides (Almeda et al. 8314). J. L. glandulifera (Almeda et al. 9700). K. L. glandulifera (Almeda et al. 9199). L. L. glandulifera (unvouchered image). Image credits: A−K. Frank Almeda; L. Livia Echternacht.

FIGURE 3. Images of Lavoisiera species. A. L. grandiflora (unvouchered image). B−C. L. grandiflora (Almeda et al. 9459). D. L. harleyi (unvouchered image). E−F. L. humilis (Almeda et al. 8497). G. L. imbricata (Almeda et al. 8497). H. L. imbricata (Almeda et al. 9032). I−K. L. itambana (Almeda et al. 9663). L. L. macrocarpa (Almeda et al. 8545). Image credits: A. Pinterest at www.pictopin.com; B, C, E−L. Frank Almeda; D. Fernando B. Matos.

FIGURE 4. Images of Lavoisiera species. A−C. L. macrocarpa (Almeda et al. 9173). D. L. mucorifera (Almeda et al. 9607). E. L. pulchella (Almeda et al. 9830). F−G. L. pulcherrima (Almeda et al. 9666). H−I. L. punctata (Almeda 9709). J. L. rigida (Almeda et al. 9089). K. L. rigida (Almeda et al. 9604). L. L. rigida (Almeda et al. 9635). Image credits: A−L. Frank Almeda.

FIGURE 32. Lavoisiera cordata. A. Habit. B. Adaxial leaf surface. C. Flower. D. Hypanthium and calyx lobes. E. Ovary crosssection. F. Petal with enlarged detail of lower margin (lower left). G. Lateral view of antesepalous stamen. H. Ventral view of antepetalous stamen. I. Seed. (Based on: A–I, Almeda et al. 8572, CAS, UEC.)

FIGURE 39. Distributions of Lavoisiera glandulifera, L. itambana, L. macrocarpa, and L. mucorifera.

FIGURE 46. Lavoisiera macrocarpa. A. Habit. B. Adaxial leaf surface. C. Flower. D. Hypanthium, calyx lobes, and ovary apex with style. E. Ovary cross-section. F. Petal with enlarged margin detail (right). G. Ventral view of antesepalous stamen. H. Ventral view of antepetalous stamen. I. Seed. (Based on: A–D, F–H, Almeda et al. 8545, CAS, UEC; E, I, Almeda et al. 8597, CAS, UEC.)