Pleroma fornograndense F.S.Mey., R.Goldenb. & L.Kollmann, 2018

Meyer, Fabrício Schmitz, Kollmann, Ludovic J. C., Fraga, Claudio Nicoletti De & Goldenberg, Renato, 2018, Four new rupicolous species of Pleroma (Melastomataceae) endemic to Espírito Santo, Brazil, Phytotaxa 348 (4), pp. 235-253 : 245-248

3. Pleroma fornograndense F.S.Mey., R.Goldenb. & L.Kollmann sp. nov. ( Figures 6–7 )

Diagnosis:— Pleroma fornograndense differs from Tibouchina radula by the prostrate habit (vs. erect in T. radula ), ovate leaves with cordate base (vs. elliptical to elliptical-lanceolate leaves with acute to obtuse base) and larger petioles (18.2–58.1 mm long vs. 10–20 mm long).

Type:— BRAZIL. Espírito Santo: Castelo, Parque Estadual do Forno Grande , 16 July 2008 (fl.), L. Kollmann & A. P. Fontana 11082 (holotype: UPCB!; Isotypes: MBML!, RB!) .

Prostrate shrub 0.8–1.8 m tall. Younger and older branches terete, both not winged, both sparsely to moderately strigose, trichomes 0.2–1.2 mm long, eglandular, appressed, narrow at the base; nodes slender. Leaves opposite; petioles 18.2– 58.1 mm long; blades 5.6–12 × 3–6.1 cm, coriaceous, concolorous, ovate, base cordate, apex acute to obtuse, 7–9 acrodromous nerves, basal, if 9 the marginals tenuous, main nerves prominent, reticulation impressed on the adaxial surface, prominent on the abaxial surface, adaxial surface bullate, rough, dark green or brown, densely scabrous, trichomes 0.8–3 mm long, eglandular, curved, enlarged at the base (bullate), abaxial surface foveolate, soft, light brown or brown, moderately strigose on the primary and secondary veins, trichomes 0.3–1.6 mm long, eglandular, appressed, narrow at the base, densely hirsutulous on the surface and tertiary veins, trichomes 0.2–0.6 mm long, eglandular, erect, narrow at the base. Thyrsoids 36–61.5 × 6.5–9 cm, terminal, axis terete, with the same indumentum as the branches, dark red; bracts late deciduous, leafy, petioles 8.3–13.7 mm long, blades 38.9–67.9 × 23.7–34.7 mm, ovate, indumentum the same as on the leaves; bracteoles early deciduous, 6.1–9.3 × 2.6–4.8 mm, ovate to lanceolate, apex acute, not covering the apex of the flower bud, margins entire, ciliate, adaxial surface glabrous, abaxial surface moderately to densely strigose, trichomes 0.3–1.4 mm long, eglandular, appressed, slightly enlarged at the base. Flowers 5-merous, pedicels 1–1.3 mm long; hypanthium 5.1–5.4 × 3–3.2 mm, oblong, not costate, moderately to densely strigose, the trichomes 0.2–1.1 mm long, eglandular, appressed, slightly enlarged at the base; sepals late deciduous, 5–6.5 × 1.9–2.1 mm, triangular, margins ciliolate, apex acute, adaxial surface glabrous, abaxial surface with the same trichomes as the hypanthium; petals purple with a white base, 23.1–25.9 × 24.1–25.2 mm, obovate, apex retuse to emarginate, forming an angle ≥ 90° in relation to the hypanthium (in living specimens); stamens 10, dimorphic, antesepalous with filaments white, 3.7–4.2 mm long, sparsely setulose on the lower two-thirds, trichomes 0.1–0.6 mm long, glandular, curved, narrow at the base, pedoconnective white, ca. 0.4 mm long prolonged below the thecae, densely to moderately setulose, trichomes 0.2–0.4 mm long, glandular, erect, narrow at the base, ventral appendages bilobed, inconspicuous,ca. 0.2 mm long, densely to moderately setulose, trichomes 0.1–0.4 mm long, glandular, erect, narrow at the base, thecae 3–3.2 × 0.4 mm, falcate to botuliform, narrow, white, antepetalous stamens with filaments white, 2.9–3.3 mm long, sparsely setulose on the lower two-thirds, trichomes 0.2–0.4 mm long, glandular, curved, narrow at the base, pedoconnective white, ca. 0.4 mm prolonged below the thecae, glabrous or sparsely setulose, trichomes ca. 0.2 mm long, glandular, curved, narrow at the base, ventral appendages bilobed, inconspicuous,ca. 0.1 mm long, glabrous or sparsely setulose, trichomes ca. 0.2 mm long, glandular, curved, narrow at the base, thecae 2.9–3.1 × 0.4–0.5 mm, widely and shortly falcate, narrow, white; ovary ca. 4.6 × 3 mm, 5-locular, apex densely sericeous, trichomes 0.2–0.6 mm long, eglandular, appressed, slightly enlarged at the base; style white, ca. 4.9 mm long, apex curved, moderately to sparsely setulose on the lower half, trichomes 0.2–0.4 mm long, eglandular, curved, slightly enlarged at the base, stigma orbicular. Velatidium 8.1–9 × 4.6–4.9 mm, costate, epicarp undivided when mature.

Paratypes:— BRAZIL. Espírito Santo: Castelo, Parque Estadual do Forno Grande , 29 January 2004 (fl.), L. Kollmann 6441 ( MBML!) ; ibidem, 31 May 2006 (fl.), L. Kollmann et al. 9144 ( MBML!, UPCB!) ; ibidem, 21 January 2009 (fr.), R. Goldenberg et al. 1281 ( MBML 37566 !, MBML 43446 !, RB!, UPCB!) ; ibidem, 20 May 2010 (fl., fr.), J. Meirelles et al. 463 ( RB!) ; ibidem, 31 October 2012 (fl., fr.), T. B. Flores & O. R. Campos 1735 ( ESA, RB!) .

Distribuition and habitat:— Pleroma fornograndense is endemic to “Parque Estadual do Forno Grande”, Espírito Santo, Brazil. It is a rupicolous plant, occuring in vegetation on granitic and gneissic inselbergs between 1000–1700 m elevation. On these places the vegetation is low, sparse, composed by shrubs and herbs.

Phenology:—Collected with flowers and/or fruits between May and January.

Conservation status:— Pleroma fornograndense is endemic to a single location, where it has been collected in two points. The AOO is 8 km 2, and the EOO is undefined. Although their populations are inside a fully protected Conservation Unit, they are small and prone to the effects of stochastic events in the near future. Therefore, following the criteria of the IUCN ( IUCN 2012), P. fornograndense should be considered as vulnerable [VU: D2].

Etymology:—The epithet derives from the locality of “Forno Grande”, where the plants come from.

Affinities:—These populations have been cited as T. radula by Meirelles & Goldenberg (2012). In fact, Pleroma fornograndense is morphologically similar to T. radula due to the leaves with a rough indumentum on the adaxial surface, ovate to lanceolate bracteoles, inflorescences in apical thyrsoids, flowers with purple petals with a white base, and antesepalous stamens with the pedoconnective covered with glandular trichomes. It differs from T. radula by the characters pointed in the diagnosis, and also by the coriaceous leaves (vs. chartaceous in T. radula ) and dark red inflorescence axes (vs. whitish).

Pleroma fornograndense is similar to P. heteromallum and its putative synonyms (see comments under P. cucculatum ) due to the ovate leaves, ovate to lanceolate bracteoles, flowers with purple petals with a white base and antesepalous stamens with the pedoconnective covered with glandular trichomes. It differs from P. heteromallum and its putative synonyms by the prostrate habit (vs. erect in P. heteromallum and its putative synonyms), coriaceous leaves (vs. chartaceous leaves), that are scabrous on the adaxial surface (vs. strigose). Pleroma fornograndense differs from P. multiflorum (one of the species synonymyzed under P. heteromallum ) by the prostate habit (vs. erect in P. multiflorum ), coriaceous leaves (vs. chartaceous leaves) that are scabrous on the adaxial surface (vs. sericeous on the adaxial surface), and strigose hypanthium (vs. sericeous hypanthium; Table 1). Pleroma fornograndense is also similar to Pleroma venetiense (see affinities for this species below).

Figures

FIGURE 6. Images of the holotype of Pleroma fornograndense. A. Branch with inflorescence. B. Detail of the leaf indumentum (adaxial surface). C. Detail of the leaf indumentum (abaxial surface). D. Detail of the indumentum on the inflorescence axis. E. Bracteoles, variation in size (abaxial surface). F. Cyme, portion of the inflorescence. G. Detail of the indumentum on the hypanthium. H1.Antesepalous stamen. H2. Antepetalous stamen. I. Gynoecium. J. Velatidium. (A–I: Kollmann & Fontana 11082, J: Goldenberg et al. 1281).

FIGURE 7. Photos of Pleroma fornograndense. A. Leaves and prostrated habit. B. Detail of the branch with reddish petioles. C. Inflorescence. D. Apex of the inflorescence. E. Flower. (Photos by L.J.C. Kollmann).