Fritzschia furnensis R. Romero & M.J.R. Rocha, 2017

Romero, Rosana & Rocha, Maria José Reis Da, 2017, Fritzschia furnensis (Marcetia alliance, Melastomataceae): an endangered new species from the State of Minas Gerais, Brazil, Phytotaxa 302 (1), pp. 49-56 : 50-54

Fritzschia furnensis R. Romero & M.J.R. Rocha , spec. nov. ( Figs. 1–3 )

Fritzschia furnensis is morphologically most similar to Comolia stenodon (Naudin) Triana and Comolia edmundoi Brade , but can be distinguished by the branches, petioles, leaves, bracteoles, pedicels, hypanthia and sepals covered by a dense indumentum with glandular trichomes that gives the plant a viscous appearance.

Type: — BRAZIL. Minas Gerais: Mun. Delfinópolis, trilha Escada de Pedras, Fazenda Zé Antunes, 20°26’04’’S, 46°38’52’’W, 841 m elev., 9 November 2005, b., fl., fr., R. Romero, J.N. Nakajima, T.M. Rezende, M.A.O. Silva & B.C. Vargas 7295 (Holotype HUFU!, isotypes BHCB!, K!).

Subshrubs or shrubs, 0.5–1 m tall, much branched, densely viscous. Young branches subquadrangular, older branches becoming rounded, glabrous and defoliating basally with age; nodes thickened. Stem bark peeling gradually in thin, woody flakes and exposing a brownish wood. Branches, petioles, bracteoles, pedicels, hypanthia and sepals covered by a dense indumentum of glandular trichomes, glands orange, brownish or dark (dry state), sometimes caducous. Leaves opposite, membranaceous, viscous, discolorous, adaxial surface dark green, abaxial surface pale green (dry state), older leaves becoming red-orange; petiole 2–10 mm long; blade (8–) 23–38 × (5.5–) 10–29 mm, ovate to ovatelanceolate, rarely lanceolate, apex acute, base rounded, margin slightly serrulate, ciliate, with glandular trichomes 0.2–0.6 mm long, 3–5-nerved from base, external pair marginal, nerves impressed on the adaxial surface, prominent on the abaxial surface, indumentum on adaxial and abaxial surfaces with pale glandular trichomes 0.1–0.3 mm long, mainly concentrated along the venation on abaxial surface. Dichasia 2–3 cm long, lateral; bracteoles 3.5–4 × 0.5–1 mm, oblong, apex acute. Flowers 4-merous, pedicel 2–4 mm long; hypanthium 4–6 × 4–4.5 mm, terete, oblong; calyx tube ca. 1 mm long; sepals 7–10 × 1–2 mm, linear-triangular, apex acute, with a short glandular trichome 0.2–0.3 mm long. Petals 15–16 × 7–10 mm, purple, oblong, apex acute, margin entire, slightly ciliate in the upper half, adaxially with glandular trichomes at the apex. Stamens 8, subisomorphic; large (antesepalous) stamens 4, filaments 10–11.5 mm long, purple, with few glandular trichomes, thecae 9–10 × ca. 0.6 mm, cream, apex attenuate, pore ventrally curved; pedoconnective 5–5.5 mm, purple, ventral appendage 0.6–0.8 mm long, purple, bilobed; small (antepetalous) stamens 4, filaments 7–8 mm long, purple, glabrous, thecae 8–8.5 × ca. 0.6 mm, cream, apex attenuate, pore ventrally curved, pedoconnective 2–2.5 mm, purple, ventral appendage 0.3–0.5 mm long, purple, bilobed. Ovary 4-locular, ca. 4 × 2.5 mm, oblong, superior, glabrous; style 16–20 mm long, purple, terete, slightly curved at the apex, glabrous or with few glandular trichomes, stigma punctiform. Capsule 4–7 × 4–5 mm, brownish; seeds 0.6–0.7 × 0.4–0.5 mm, brownish, shiny, numerous, cochleate, testa tuberculate.

Habitat and Distribution: — Fritzschia furnensis is endemic to campos rupestres in Minas Gerais state, occurring in rocky outcrops in grassland or in shady, moist areas close to rivers. To date F. furnensis is known only from a few populations in a restricted area from Delfinópolis ( Silva & Romero 2008) and Capitólio municipalities ( Romero & Versiane 2014).

Conservation Status: — All known collections of this species come from six populations from Capitólio and three from Delfinópolis. None of the populations occur in a officially protected area. Based on georeferenced data from cited collections, the area of occupancy was calculated using GeoCAT ( Bachman et al. 2011). As F. furnensis has an area of occupancy of less than 20 km 2, and occurs in an area with intensive rock extraction for commercial purposes and its habitat is under threat from fire, it should be considered EN B1ab(iii)+2ab(iii) according to the IUCN categories and criteria (2001, 2016).

Etymology: — The specific epithet was chosen since this species has a restricted occurrence in the campos rupestres close to the Furnas hydroelectric power station.As for Microlicia furnensis R. Romero (2014: 119) , which was recently discovered near Furnas, we chose the epithet to show that this species is also endemic to the region. Moreover, we expect it to be a warning for the Brazilian government and the local community on the plant diversity in this region and the potential of the area for the establishment of a protected area as suggested by IBAMA (2005).

Phenology: — Flowering in May, July, and September through December; fruiting January, February, April, May, September to November.

Specimens Examined: — BRAZIL. Minas Gerais: Mun. Delfinópolis, Fazenda Paraíso, estrada para Casinha Branca , “Condomínio de Pedras”, 20°26’04’’ S, 46°38’52’’ W, 841 m elev., 11 April 2002, fr., R. A. Pacheco et al. 162 ( HUFU) ; Trilha Escada de Pedras, Fazenda Zé Antunes , 20°26’04’’S, 46°38’52’’W, 841 m elev., 11 October 2002, b. fl., fr., R. Romero et al. 6454 ( HUFU) ; Paraíso Selvagem, trilha para cachoeira Salto Solitário , 20°26’04’’S, 46°38’73’’W, 845 m elev., 4 December 2002, b., fl., fr., J.N. Nakajima et al. 3327 ( HUFU) ; Mun. Capitólio: estrada Furnas-Capitólio, mais próximo à Furnas , logo após a ponte da represa, 13 February 1998, fr., R. Romero et al. 5081 ( UEC) ; Chapadão de Furnas, Córrego da Quadra , 1175 m elev., 23 September 2001, fl., fr., R. Romero 6181 ( HUFU, UB) ; Chapadão de Furnas , 20°37’12’’ S, 46°16’33’’ W, 1175 m elev., 24 January 2002, fr., R. Romero 6202 ( CEN, HUFU) ; Estrada para Gabi Exploração I, região de Furnas , 22 May 2005, fl., P.H.N. Bernardes et al. 197 ( HUFU, P) ; Cachoeira Fecho da Serra, Rio Turvo , 20°36’16’’ S, 46°13’51’’ W, 786 m elev., 28 September 2005, fl., fr., R. Romero et al. 7186 ( HUFU, NY, US) ; estrada para Pedreira Souza, ca. 2 km da MG 050, região da Represa de Furnas , 7 December 2005, fl., fr., J.N. Nakajima et al. 4052 (F, HUFU, P) ; região da Represa de Furnas , 13 July 2006, b., fl., A.A. Arantes 1997 ( CESJ, HUFU) ; estrada para Cachoeira Fecho da Serra , região da represa de Furnas, 24 October 2006, fl., fr., R. Romero et al. 7874 ( BHCB, HUFU, RB, SP) ; estrada para Pedreira, ca. 2 km do Lago Azul, Região de Furnas , 7 November 2007, fr., R. Romero et al. 7981 ( HUFU, R) ; Pousada do Rio Turvo, trilha para Cachoeira do Fecho , 4 November 2008, fl., fr., L.S. Kinoshita et al. 08-62 ( HUFU, UEC) ; estrada para Gabi Exploração II, ca. 8 km, região de Furnas , 8 November 2007, fl., fr., R. Romero et al. 8036 ( HUFU, K, P) ; Pousada do Rio Turvo, trilha para cachoeira do Fecho , 4 November 2008, fl., fr., L.S. Kinoshita et al. 08-59 ( HUFU, UEC) ; estrada para Pedreiras , 20°36’13’’ S, 46°17’36’’ W, 999 m elev., 5 November 2008, fl., L.S. Kinoshita et al. 08/440 ( HUFU, UEC) ; estrada de acesso à Cachoeira do Fecho , 20°38’11’’ S, 46°13’43’’ W, 18 May 2013, fr., M.J.R. Rocha & R.P.M. Pena 984 ( BHCB) .

Discussion: — The combination of leaves, petioles, sepals and anthers of larger dimensions, and viscous leaves with glandular ciliate and slightly serrulate margins are remarkable features and distinguish this species from all others ( Table 1). Four of the five species recognized in Comolia sect. Tricentrum [ Comolia edmundoi Brade (1959: 11) , Comolia lanceiflora ( Candolle 1828: 118) Triana (1872: 37) , Comolia sessilis ( Sprengel 1825: 303) Triana (1872: 37) , and Comolia stenodon (Naudin) Triana ] are morphologically related to Fritzchia furnensis and have very similar floral features. Fritzschia furnensis differs from C. stenodon , which occurs in campos rupestres between Serra do Cipó and Diamantina ( Seco 2006) , in the Espinhaço Mountain Range, by the eglandular trichomes on the leaves, and the smaller leaves (10 − 25 × 4–12 mm) in the axils of larger leaves forming a pseudo-fascicle, with strongly serrate margins. It differs from C. edmundoi Brade , which is endemic to Diamantina, by having sessile leaves or with a short petiole (up to 2 mm long), cordiform leaf blade, terminal inflorescence subtended by foliaceous bracts and a short pedicel ca. 1 mm long ( Brade 1959) in the latter. Comolia lanceiflora , which also occurs in Goiás state ( Fig. 4 ), has a terminal inflorescence subtended by foliaceous bracts and flowers with a short pedicel (ca. 1 mm long). Comolia sessilis , which is endemic to Minas Gerais state in the Espinhaço Mountain Range, has sessile leaves or with a short petiole (up to 2 mm long), cordate leaf blade, and axillary and solitary flowers. Comolia sertularia ( Candolle 1828: 125) Triana (1872: 37) is the only species in the section Tricentrum that has small leaves. It is endemic to Minas Gerais state occuring exclusively in the Espinhaço Mountain Range and is a remarkable species by having sessile and small leaves (2 × 1 mm), subcordiform to oblong blade, cordate base, strongly revolute margins, with solitary flowers in a short pedicel (ca. 1 mm long). Romero and Versiane (2014) listed the species of Melastomataceae from Serras de Capitólio and indicated the gathering R. Romero et al. 8036 as Comolia sp. nov.

Figures

FIGURE 1. A–L Fritzschia furnensis. A. Flowering branch. B. Indumentum of the branch. C. Stem peeling off. D. Flower bud, showing hypanthium and sepals. E. Flower. F. Capsule. G. Lateral view of antepetalous stamen. H. Lateral view of antesepalous stamen. I. Gynoecium. J. Connective with ventral appendage—antepetalous stamen. K. Connective with ventral appendage—antesepalous stamen. L. Ovary apex. (From R. Romero et al. 7295).

FIGURE 2. A–D Fritzschia furnensis. A. Vegetative branches. B. Branch with mature fruits. C. Stem peeling off. D. Habitat in Capitólio (M.J.R. Rocha & R.P.M. Pena 984). Photo: M.J.R. Rocha.

FIGURE 3. A–F General features of seeds and leaf indumentum of Fritzschia furnensis (SEM). A. Lateral view. B. Detail of arrangement of the cells. C. Antiraphal view. D. Raphal view. E. Leaf indumentum on abaxial surface. F. Detail of glandular trichome.

FIGURE 4. Distribution of species of Comolia sect. Tricentrum and Fritzschia that are almost endemic to Minas Gerais state, Brazil, except of Comolia lanceiflora, that also occurs in Goiás state.