Pleroma marinana P. J. F. Guim. & Fraga 2014, sp. nov.
Creators: name: Fraga, Claudio Nicoletti De
name: Guimarães, Paulo José Fernandes
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Melastomataceae
Pleroma
Pleroma marinana

description: 1. Pleroma marinana P.J.F. Guim. & Fraga, sp. nov. (Figs. 1, 2).
Tibouchina oreophila Wurdack affinis, foliis supra scabris pilis uncinatis obsitis similis, sed connectivo sub anthera glabra differt. Tibouchina radula Markgraf aeque affinis, foliis scabri et connectivo sub anthera glandulosa similis, sed foliis supra dense strigose cum pilis base bullato ramoso et subtus sericeo differt.
Type: — BRAZIL. Espírito Santo: Mun. Pancas, Serra do Mutum Preto, elev. 750 m, 7 March 2003, C. N. Fraga; H. Q. Boudet Fernandes & R. R. Vervloet 962 (holotype: MBML!; isotypes: K!, CEPEC!, NY!, RB!, UPCB!).
Shrub 3 m tall; stems, branches, petioles, inflorescences, hypanthium, calyx lobes and ovary apex scabrous, densely covered by short strigose trichomes; stems and young branches 4-angled. Leaves opposite; petioles 1–2.5 cm, cylindrical, reddish on young leaves; blades 3–10 × 2–5.5 cm, rounded or ovate, base cuneate to rounded, margins entire, apex obtuse sometimes retuse, chartaceous to subcoriaceous, 7-nerved, external pair marginal, venation prominent on the abaxial surface and impressed on the adaxial surface, adaxial surface strigose, trichomes bulla-based, conical, abaxial surface with strigose trichomes on transverse veins and stellate trichomes above the reticulation, both kinds of trichomes white when fresh and yellowish when dried. Thyrses ca. 20 cm long, terminal, erect; bracteoles caducous, 2.5–3 × 1.5–2 mm, green, lanceolate, symmetrical, concave, apex acute, adaxial surface densely covered with strigose trichomes, abaxial surface glabrous. Flowers 5-merous, subsessile, pedicels 1–1.5 mm long.; hypanthium 4.5–5 × 4–4.5 mm, green with reddish trichomes in fresh flowers; calyx lobes 4.5–5 × 2.5– 3 mm, lanceolate, asymmetric, apex acute, glabrous abaxially, densely covered with white to reddish trichomes at the base and along central vein adaxially, margins ciliate, caducous in fruit; petals 18–20 × 18–20 mm, obovate, apex truncate, margin shortly ciliate, purple and white at the base, changing to red later; stamens 10, dimorphic, filaments cream, covered with glandular trichomes at the base, antesepalous 4–5 mm long and antepetalous 3–3.5 mm long, connective prolonged ca. 1 mm long, antesepalous covered with reddish glandular trichomes and antepetalous glabrous, anthers subulate, 3–3.5 mm long, antesepalous purple, with reddish glands on the connective, antepetalous cream, with an apical ventrally inclined pore; ovary 5-celled, half inferior; style sigmoid, covered with glandular trichomes at the basal half, stigma truncate. Capsule 5–5.6 × 4.5–5 mm, globose; seeds 0.26–0.35 mm long, 0.39–0.45 mm diam., numerous, cochleate, testa tuberculate.
Etymology: — The specific epithet honors Maria Osmarina Marina Silva Vaz de Lima, Brazil’s Environment Minister from 2003 to 2008, who played an important role on the creation and maintenance of protected natural areas in Brazil.
Distribution and habitat: — The new species is endemic to the municipality of Pancas from ca. 750 m elevation, Espírito Santo, Brazil (fig. 3). This region is characterized by granitic and gneissic inselbergs, which rise more or less abruptly above the surrounding landscape dominated by the Tropical Semideciduous Forest. The habitat of P. marinana is characterized by rather sparse vegetation, with thickets of shrubs among an herbaceous layer that usually dries in the dry season (Fig. 2).
Conservation: — The new species is endemic, and its populations are represented by scattered individuals, with EOO estimated as 0.04 km 2, and AOO estimated as 8 km 2. All populations were found outside protected areas, in an region prone to the effects of human activity (livestock raising, agriculture, and commercial granite exploitation). This species is also prone to the effects of stochastic events, within very near future, and must be included in the vulnerable category [VU D2].
Paratypes:— BRAZIL. Espírito Santo: Municipality of Pancas, Serra do Mutum Preto, 785 m, 30 October 2003, C.N. Fraga, B.R. Silva, A.P. Fontana & R.R. Vervloet 1080 (MBML, RB). Idem, Pedra da Colina, 768 m, 18 January 2008, V.F. Mansano, E.F. Guimarães, F. Filardi, L. Araújo & G. Haiden 536 (RB). Idem, Pedra da Colina, 19°13’51” S, 40°52’35” W, 700 m, 12 March 2010, D.P. Saraiva, J. Silva, K.V. Hmeljeviski, R.C. Forzza 35 (MBML, UPCB). Idem, Serra do Alto Mutum Preto, Pedra da Colina, “caminho para a rampa de vôo livre”, 19°13’51” S, 40°52’35” W, 765 m, 13 April 2013, C.N. Fraga, H.C. Lima, R. Gribel & M. Lemes 3500 (CEPEC, HUEFS, K, MBML, NY, RB, SPF).
Comments: — Pleroma marinana can be distinguished by the stellate trichomes on the abaxial leaf surface and the presence of dimorphic stamens. Tibouchina radula Markgraf (1930 [1927]: 49) and T. oreophila Wurdack (1981: 305) are closely related. Tibouchina radula also occurs at Espírito Santo inselbergs from 1000 to 1300 m elevation, while T. oreophila occurs in Bahia, on the rocky outcrops of Pico das Almas, at 1400–1800 m elevation (Guimarães 1997; Freitas 2011). Tibouchina radula has stamens similar to those of P. marinana but is distinguished by the strigose bulla-based, roughened, and branched trichomes on its adaxial leaf surface, whereas T. oreophila has the adaxial leaf indument very similar to that of P. marinana but is distinguished by its isomorphic glabrous stamens. These two species also differ from T. marinana by the indument of their abaxial leaf surface, with uncinate dendritic trichomes in T. oreophila and short and sericeous ones in T. radula. The abaxial leaf surface in P. marinana is densely covered with stellate trichomes between the transverse nerves and by strigose trichomes on the other nerves.
description: Published as part of Fraga, Claudio Nicoletti De & Guimarães, Paulo José Fernandes, 2014, Two new species of Pleroma (Melastomataceae) from Espírito Santo, Brazil, pp. 77-84 in Phytotaxa 166 (1) on pages 78-81, DOI: 10.11646/phytotaxa.166.1.5, http://zenodo.org/record/5138231