Bertolonia organensis Baumgratz, Gonçalves-Silva & Nunes-Freitas, 2016

Silva-Gonçalves, Kelly Cristina Da, Baumgratz, José Fernando A. & Nunes-Freitas, André Felippe, 2016, A new species of Bertolonia (Melastomataceae) from the Southeastern Brazilian Atlantic Forest, Phytotaxa 273 (2), pp. 115-121 : 116-119

Bertolonia organensis Baumgratz, Gonçalves-Silva & Nunes-Freitas sp. nov. ( Figures 1–2 )

Bertolonia organensis closely resembles B. carmoi Baumgratz (1990: 120) , B. maculata DC. (1828: 114) and B. marmorata ( Naudin 1848: 382) Naudin (1851: 318) , due to the size, cordate base and variegated adaxial surface of the leaves and the dorsally appendaged connectives. However, the latter are distinguished mainly by the leaves with 3-5 acrodromous veins and the membranaceous, oblong, obovate or ovate calyx lobes, with a rounded, obtuse or truncate apex and ciliate-glandulose margins.

Type: — BRAZIL. Rio de Janeiro: mun. Magé, Distrito de Santo Aleixo, Parque Nacional da Serra dos Órgãos, trilha da Cachoeira Grande, após o reservatório da CEDAE, em Floresta Ombrófila Densa Submontana alterada, 22°34’23”S, 43°07’49”W, 236 m, local úmido, com solo argiloso, humoso e sombreado, January 2012, fl., fr., Baumgratz et al. 1187-A (holotype RB!).

Herbs 5–15 cm tall, terrestrial, prostrate; indumentum of the stem, leaves, inflorescences, bracts, bracteoles, hypanthium and calyx glandulose-punctate and sparsely setulose and setulose-glandulose, glandular head caducous or not; adventitious roots along the stem, mainly at its basal portion, short to long, branched; stem 0.9–2.5 cm long, usually single, subterete. Leaves opposite, apparently in a rosette due to the short stem; petiole 0.8–5.9 cm long, vinous, semi-terete; lamina 2.8–13 × 2.7–10 cm, discolor, adaxial surface variegated, with dark green to vinous bands along the acrodromous veins or green, abaxial surface vinous, bullate and shiny on adaxial surface, foveolate on abaxial surface, rigid-membranaceous, elliptic to ovate, base cordate, apex acute to obtuse, margin sparsely serrateciliate; veins 7, acrodromous basal; domatia axilar-primary on the abaxial surface, marsupiform, inconspicuous. Inflorescences ca. 6 cm long (5–12.5 cm long in fruiting), scorpioid cymes or dichasia of scorpioid cymes, vinous, terminal (pseudo-axillary in late fruiting), peduncle ca. 1.2 cm long, rachis ca. 4.8 cm long (4.7–7 cm long in fruiting), tetragonal; bracts 2.9–3.5 × 0.5–0.9 mm, bracteoles 1.5–1.8 × 0.3–0.4 mm, both narrow-triangular, apex acuminate-glandulose, persistent or late caducous. Flowers 5-merous, 13.5–15.8 mm long; pedicel ca. 1.3 mm long; hypanthium ca. 2.5 × 3 mm, thick, shortly tubulose, caducous in fruiting; inner torus glabrous; calyx 1.2–1.3 mm long, thick, caducous in fruiting, tube 0.4–0.5 mm long, external lobes 1.8–1.9 × 1.2–1.3 mm, erect, narrow-triangular, apex acuminate-glandulose, margin entire, not ciliate, with three vascular bundles, internal lobes inconspicuous, reduced to a lightly sinuate sheath ca. 0.1 mm long, membranaceous; petals 10–12 × 6–6.5 mm, light pink, patent, obovateasymmetric, apex acute and apiculate-glandulose with 1-2 unbranched trichomes, margin entire, glabrous; stamens 10, subequal in size and shape, anthers narrow-triangular, thecae undulate, connective not prolonged below thecae, dorsally appendaged, pore terminal-ventral, antesepalous 6.1–7.5 mm long, with filaments 3.5–4.5 mm long, anthers 2.7–3 × 0.5–0.6 mm, appendage trilobate, lateral lobes larger (0.3–0.4 mm long) than the median lobe (0.2–0.25 mm long), acute to obtuse, antepetalous 5.5–6.1 mm long, with filaments 3–3.5 mm long, anthers 2.5–2.6 × 0.5–0.6 mm, appendage 0.4–0.6 mm long, acute calcar; ovary 2–2.1 × 2.2–2.3 mm, free inside the hypanthium, oblong, 3-celled, apex lobulate, thick, glabrous; style ca. 6 mm long, terete, slightly curved at the apex, stigma capitate. Fruits capsular, bertolonidium type, 4–6 × 5.5–6.6 mm, obtriquetrous, polispermic; placenta linear-subulate, lightly verrucose; seeds 0.4–0.5 × 0.3–0.6 mm, clavate or obovate to triangular, rostrate at the apex, rostrum 0.1–0.2 mm long, horizontal to erect, tuberculate at the dorsal angles and apex.

Material Examined: — BRAZIL, Rio de Janeiro: mun. Magé, Distrito de Santo Aleixo, Parque Nacional da Serra dos Órgãos, trilha da Cachoeira Grande, após o reservatório da CEDAE, em Floresta Ombrófila Densa Submontana alterada, local úmido, humoso e sombreado ; 22°34’23”S; 43°7’49”W; 236 m alt., Nov. 2011, fr., J.F.A. Baumgratz et al. 1186, 1187 ( RB) ; 24 Mar 2011, fr., L.A.F. Santos Filho et al. 178, 179, 180, 181 ( RB) .

Etymology: —The epithet “ organensis ” refers to the name of the national park where the species occurs.

Distribution and Habitat: — Bertolonia organensis is endemic to Brazil, and it was found in a single locality in southeastern Rio de Janeiro state, municipality of Magé, district of Santo Aleixo, in Serra dos Órgãos National Park, in the southeastern Serra do Mar range. It is restricted to Serra dos Órgãos, in Atlantic Rain Forest (Floresta Ombrófila Densa Submontana), at about 230 m elev., growing on clay soil at a shaded hillside bordering the trail, beneath a rock outcrop. The Serra dos Órgãos National Park is a Federal Conservation Unit established in 1939. It has a very rugged topography, with ca. 20.024 ha, and a wide altitudinal range (100 to 2.263 m), with the ocean side wetter than the north and west faces. The average annual temperature is between 13 and 23 °C and it is covered with dense submontane to high montane tropical rainforests (Floresta Ombrófila Densa Submontana, Montana and Alto-Montana), including high altitude grasslands (Campos de Altitude) ( Cronemberger & Castro 2007).

Comments: — Bertolonia organensis is distinguished by the glandulose-punctate, sparsely setulose and setulose-glandulose indumentum, and the leaves with 7 acrodromous veins, bullate on adaxial surface. The hypanthium is shortly tubulose, and the external calyx lobes are erect, thick, narrow-triangular, with an acuminate-glandulose apex and an entire, not ciliate margin. The anthers connective is dorsally appendaged, trilobed or with an acute calcar. The stem is usually unbranched, but sometimes a branch may occur at its distal portion.

The new species is closely similar to B. carmoi , B. maculata and B. marmorata , which share the setulose and setulose-glandulose indumentum, variegated elliptic to ovate leaves with similar size and cordate base, and also with the connective with a short dorsal appendage.All these three species differ from B. organensis mainly by the leaves with 3-5 acrodromous veins, the membranaceous, oblong, obovate or ovate calyx lobes with a rounded, obtuse or truncate apex and ciliate-glandulose margins. Bertolonia carmoi and B. marmorata are restricted to northeastern Brazil: the former is endemic to Bahia state and the latter occurs in Bahia and Pernambuco states. These three species can also be distinguished from B. organensis by other characteristics: Bertolonia carmoi has longer stamens (8.2–9.5 mm), linear-falciform anthers, plane, sometimes lightly undulate thecae, and rounded to truncate connective appendages; Bertolonia maculata has anthers with a truncate-emarginated apex and a terminal pore, and unappendaged connectives, sometimes slightly gibbose at the base; and Bertolonia marmorata has shorter flowers (8–13 mm) and petals (6.5–8 mm), anthers that are clearly undulate, gibbose and calloused on the base, sometimes with an inconspicuous calcar, and the pore with convolute and thickened margins forming evident protrusions.

Bertolonia organensis also resembles B. hoehneana Brade (1956: 225) , B. nymphaeifolia Raddi (1820: 384) , B. sanguinea Saldanha ex Cogn. var. sanguinea (1886: 51) and B. sanguinea var. santos-limae ( Brade 1956: 223) Baumgrtaz (1990: 109) in the shape and cordate base of the leaves. While B. hoehneana is endemic to the state of São Paulo and B. sanguinea var. sanguinea and B. sanguinea var. santos-limae endemic to Rio de Janeiro state, B. nymphaeifolia occurs in Minas Gerais, Rio de Janeiro and São Paulo. These taxa are distinguished from B. organensis by different sets of characteristics: B. hoehneana has leaves with 3-5 acrodromous veins, shorter flowers (10–13 mm) and petals (6.3–7.1 mm) and fleshy, widely ovate, calyx lobes with acute, not glandulose apex; B. nymphaeifolia has leaves with 7-9 acrodromous veins, widely campanulate hypanthia, a cupuliform corolla, external calyx lobes reduced to a membrane forming a shallow pocket-like cavity and rounded at the apex; B. sanguinea var. sanguinea and B. sanguinea var. santos-limae have widely elliptic or ovate to orbicular leaves, glandulose-punctate and hirsute petioles, cupuliform corollas, patent to reflex, widely ovate, external calyx lobes with an acute apex, and longer floral parts: hypanthium (4–6.5 mm), filaments (8–9 mm), anthers (9–10 mm) and style (12–13 mm).

Bertolonia alternifolia Baumgratz, Amorim & A.B. Jardim (2011: 273) and Bertolonia bullata Baumgratz, Amorim & A.B. Jardim (2011: 276) share with B. organensis the setose- or setulose-glandulose indumentum and leaves with a cordate base. The former species can be distinguished mainly by the alternate leaves along the stem and the latter by the leaves bullate on the adaxial surface and foveolate on abaxial surface, the exclusively glandulose-punctate indumentum of the pedicel, hypanthium and calyx, oblong bracts and bracteoles with an acute to acuminate, not glandulose apex, and shorter and wider external lobes. Furthermore, both species are endemic to southeastern Bahia state.

Three additional species, B. formosa Brade (1956: 224) , B. foveolata Brade (1956: 226) and B. wurdackiana Baumgratz (1990: 125) , all endemic to Espírito Santo state, also have leaves with a cordate base and the last two species have leaves bullate on the adaxial surface and foveolate on the abaxial surface. Bertolonia formosa differs from B. organensis by the leaves that are not bullate nor foveolate, the widely campanulate and densely villose hypanthium, and costate calyx lobes on the abaxial surface with shortly laciniate margins. Bertolonia foveolata can be distinguished by the villose stem, petioles and leaf adaxial surface; and B. wurdackiana by the tomentose stems and petioles, leaves adaxial surfaces sparsely strigose and calyx lobes with laciniate margins.

Figures

FIGURE 1. Bertolonia organensis Baumgratz, Gonçalves-Silva & Nunes-Freitas: a–b. habit and infructescences; c. detail of the abaxial leaf blade, stem and roots; d. inflorescence with flower buds (Photos by J. F. A. Baumgratz).

FIGURE 2. Bertolonia organensis Baumgratz, Gonçalves-Silva & Nunes-Freitas: a. habit; b. details of the petiole and acrodromous veins on the abaxial leaf surface; c–d. details of abaxial and adaxial surfaces of the leaf, respectively; e. flower; f. bracteole; g–h. details of the petal apex with two and one glandular trichomes, respectively; i. antesepalous stamen; j. antepetalous stamen; k. hypanthium and calyx; l. detail of the trilobate connective appendage of the antesepalous stamen, lateral view; m. detail of the calcar on the connective of the antepetalous stamen, lateral view; n. detail of the trilobate connective appendage of the antesepalous stamen, dorsal view; o. style; p. ovary free inside the hypanthium; q. ovary in transversal section; r. fruits and bracteoles; s. seeds (Baumgratz 1187-A).