Pleroma cucullatum F.S.Mey., Fraga & R.Goldenb., 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 : 237-242

1. Pleroma cucullatum F.S.Mey., Fraga & R.Goldenb. sp. nov. ( Figures 2–3 )

Diagnosis:— Pleroma cucullatum differs from Pleroma marinanum by the leaves with adaxial surface flat and soft (vs. bullate and rough in P. marinanum ), sericeous to sericeous-dendritric (vs. scabrous), with trichomes 2.5–3.3 mm long (vs. trichomes 1.3–1.6 mm long). It also differs from P. marinanum by the cucullate bracteoles (vs. lanceolate to triangular bracteoles), with the apex covering the flower bud (vs. the apex not covering the flower bud).

Type:— BRAZIL. Espírito Santo: Nova Venécia, Área de Proteção Ambiental —APA da Pedra do Elefante , 19 February 2008 (fl.), L. Kollmann, C. N. Fraga & A. P. Fontana 10701 (holotype: UPCB!; Isotypes: CEPEC!, RB!) .

Erect shrub 0.8–2 m tall. Younger and older branches terete, both not winged, both moderately to densely setose, trichomes 1.4–2.9 mm long, eglandular, curved, slightly enlarged at the base; nodes slender or thickened. Leaves opposite; petioles 13.4–50.6 mm long; blades 6.1–13.7 × 4.7–10.8 cm, chartaceous, concolorous, ovate to rounded, base rounded to cordate, apex acute or apiculate, 5–7 acrodromous nerves, if 7 the marginals tenuous, main nerves prominent, reticulation impressed on the adaxial surface, prominent on the abaxial surface, adaxial surface flat, soft, green or yellowish green, densely sericeous to sericeous-dendritric, trichomes 2.5–3.3 mm long, eglandular, curved, slightly enlarged at the base (bullate), where they can be branched or not, abaxial surface flat, soft, yellow or brown, densely setose on the primary and secondary veins, trichomes 1.9–2.6 mm long, eglandular, curved, enlarged at the base, densely villose to villose-dendritic on the surface, tertiary and quaternary veins, trichomes 0.4–0.8 mm long, eglandular, coiled, narrow and usually branched at the base. Thyrsoids 15–29 × 6–13 cm, terminal, axis rounded to subterete, with the same indumentum as the branches, yellowish-green (base) to reddish yellow (apex); bracts late deciduous, leafy, petioles 2.5–6.8 mm long, blade 20–32.1 × 11.8–28.7 mm, ovate to elliptic, indumentum the same as on the leaves; bracteoles late deciduous, 7.9–13.6 × 7.3–12.8 mm, cucullate, apex rounded, covering the apex of the flower bud, margins entire, ciliate, adaxial surface glabrous, abaxial surface moderately setose, trichomes 1.1–2.9 mm long, eglandular, curved, slightly enlarged at the base. Flowers 5-merous, pedicels 1.2–1.8 mm long; hypanthium 7.1– 7.9 × 5.2–6 mm, oblong, tenuously costate, densely setose, trichomes 1.2–2.7 mm long, eglandular, curved, enlarged at the base; sepals early deciduous, 6.1–6 × 3.4–3.8 mm, oblong, margins ciliolate, apex acute, adaxial surface glabrous, abaxial surface with the same trichomes as the hypanthium; petals purple with a white base, 26.2–29.3 × 26.7–29.4 mm, obovate, apex retuse to emarginate, forming an angle ≥ 120° in relation to the hypanthium (in living specimens); stamens 10, dimorphic, antesepalous with filaments white, 7–7.3 mm long, densely to moderately setulose on the lower two-thirds, trichomes 0.3–1.1 mm long, glandular, curved to erect, narrow at the base, pedoconnective white, 0.9–1.2 mm prolonged below the thecae, densely to moderately setulose, trichomes 0.3–0.6 mm long, glandular, erect, narrow at the base, ventral appendages bilobed, inconspicuous, ca. 0.2 mm long, sparsely setulose, trichomes 0.2–0.4 mm long, glandular, erect, narrow at the base, thecae 5.7–6.2 × 0.4–0.6 mm, falcate, narrow, purple, antepetalous stamens with filaments white, 5.8–6 mm long, densely setulose on the lower two-thirds, trichomes 0.2–0.9 mm long, glandular, curved to erect, narrow at the base, pedoconnective white, 0.9–1.1 mm, prolonged below the thecae, glabrous or sparsely setulose, trichomes 0.2–0.4 mm long, glandular, erect, narrow at the base, ventral appendages bilobed, inconspicuous, ca. 0.2 mm long, glabrous or with the same trichomes as the pedoconnective, thecae 4.8–5 × 0.6–0.7 mm, widely and shortly falcate, narrow, white or light purple; ovary 6.6–6.9 × 4–4.2 mm, 5-locular, apex densely sericeous, trichomes 0.8–1.5 mm long, eglandular, appressed, narrow at the base; style white or light purple, 6.9–7.3 mm long, apex curved, moderately to densely setulose on the lower two-thirds, trichomes 0.6–0.9 mm long, eglandular, curved, slightly enlarged at the base, stigma orbicular. Velatidium 8.1–8.8 × 5.2–7.9 mm, costate, epicarp undivided when mature.

Paratypes:— BRAZIL. Espírito Santo: Nova Venécia, Área de Proteção Ambiental – APA da Pedra do Elefante , 18 February 2008 (fl.), C. N. Fraga et al. 1895 ( CEPEC!, MBML!, RB!, UPCB!) ; ibidem, 19 February 2008 (fl., fr.), C. N. Fraga et al. 1908 ( CEPEC!, MBML!, RB!, UPCB!) ibidem, 09 May 2008 (fl., fr.), A. P. Fontana et al. 5235 ( CEPEC!, MBML!, RB!, UPCB!) ; ibidem, 29 April 2008 (fl.), L.Kollmann et al. 11011 ( MBML!) ; ibidem, 17 July 2008 (fl.), R. C. Forzza et al. 5166 ( RB!, UPCB!) ; ibidem, 10 May 2008 (fr.), R. Goldenberg et al. 1143 ( MBML!, RB!, UPCB!) ; ibidem, 14 January 2009 (fl.), P. H. Labiak et al. 5109 ( CEPEC!, MBML!, RB!, UPCB!) ; ibidem, 15 April 2009 (fl.), C. N. Fraga & R. C. Forzza 2534 ( MBML!, RB!, UPCB!) ; ibidem, 26 April 2010 (fl.), A. M. Assis et al. 2465 ( K, MBML!, UPCB!) ; ibidem, 24 April 2013 (fl.), M. O. O. Pellegrini 383 ( MBML!, UPCB!) ; ibidem, 16 March 2016 (fl.), L. F. A. Paula et al. 943 ( RB!, UPCB!) ; ibidem, 16 March 2016 (fl.), L. F. A. Paula et al. 945 ( RB!, UPCB!) ; ibidem, 21 March 2016 (fl.), H. V. Pinto Junior & C. Covre 264 ( SAMES, UPCB!) ; ibidem, 15 December 2016 (fl.), L.Kollmann et al. 13242 ( BHCB, MBML!, SP!, VIES!). São Gabriel da Palha , afloramento ao lado de um laticínio, 17 March 2016 (fl.), L. O. Azevedo et al. 444 ( RB, UPCB!) ; ibidem, 17 March 2016 (fl.), L. O. Azevedo et al. 447 ( RB, UPCB!) .

Distribuition and habitat:— Pleroma cucullatum is a rupicolous plant occuring on granitic and gneissic inselbergs at “Pedra do Elefante”, in Espírito Santo, Brazil, and other nearby inselbergs. It occurs between 250–700 m elevation, in places with sparse vegetation, composed by shrubs and herbaceous plants.

Phenology:—Collected with flowers between December and July, and with fruits between February and May.

Conservation status:— Pleroma cucullatum is represented by a few populations with scattered individuals. The Area of Occupancy (AOO) is 12 km 2, and the Extent of Occurrence (EOO) 4.437 km 2. Although some populations are inside a Conservation Unit (CU), they are still at risk because this CU is an “Área de Proteção Ambiental” (Environmental Protection Area), which means that human activity is only partially restricted. Fires are common in the surroundings, especially in the drier seasons, for pastures renovation and land cleaning for plantations. Granite mining activities are frequent in the region, being one of the main threats to the species. Therefore, following the criteria of the IUCN ( IUCN 2012), P. cucullatum should be considered as Critically Endangered [CR: B1ab(i,ii,iii,v)].

Etymology:—The epithet is related to the distinctive cucullate bracteoles on floral buds.

Affinities:— Pleroma cucullatum is morphologically similar to P. marinanum ; both occur in inselbergs in the state of Espírito Santo, are erect shrubs with ovate to rounded leaves, these with conspicuous petioles (10–50.6 mm long in P. cucullatum , 10–25 mm long in P. marinanum ), and the adaxial surface bullate. Both have setose hypanthia, flowers with purple petals with a white base, and the antesepalous stamens with glandular pedoconnective and appendages. Pleroma cucullatum differs from P. marinanum by the characters pointed in the diagnosis, and also by the larger hypanthia with 7.1–7.8 × 4.7–5.3 mm (vs. 4.5–5 × 4–4.5 mm in P. marinanum ), and abaxial leaf surface with unbranched or dendritic trichomes (vs. stellate trichomes).

Pleroma cucullatum also resembles P. heteromallum and another species sometimes listed as its synonym, Pleroma multiflorum (see Guimarães 1997), due to the oval leaves, with large petioles (10.2–28 mm long), flowers with purple petals with a white base and antesepalous stamens with glandular pedoconnective and appendages. Pleroma cucullatum differs from P. heteromallum and other putative synonyms indicated by Guimarães (1997) [ Pleroma adenostemon ( Candolle 1828: 130) A. Gray (1854: 603 43), Tibouchina gardneri ( Naudin 1849: 140) Cogniaux (1885: 334) , Pleroma villosissimum Triana (1873: 43) , Tibouchina decemcostata Cogniaux (1885: 331) , Tibouchina grandifolia Cogniaux (1885: 335) and Tibouchina magdalenensis Brade (1938:74) ], by the late deciduous, cucullate bracteoles with the apex covering the flower bud (vs. early deciduous, oval to lanceolate bracteoles with the apex not covering the flower bud in P. heteromallum and its putative synonyms). Pleroma cucullatum differs from P. multiflorum by the adaxial surface of the leaves with trichomes slightly enlarged at the base (vs. trichomes with a narrow base in P. multiflorum ), setose hypanthium (vs. sericeous), and bracteoles with the apex covering the flower bud (vs. bracteoles with the apex not covering the flower bud; Table 1).

Pleroma cucullatum is also similar to T. tedescoi . Both are erect shrubs with ovate leaves that are sericeous on the adaxial surface, with conspicuous petioles (13.4–50.6 mm long in P. cucullatum , 5–24 mm long in T. tedescoi ). It differs from T. tedescoi by the rounded bracteoles, with the apex covering the flower bud (vs. ovate to lanceolate bracteoles, with the apex not covering the flower bud in T. tedescoi ) and by the stamens from both cycles with glandulose pedoconnective and appendages (vs. glabrous).

The cucullate bracteoles of Pleroma cucullatum can also be found in the recently described Pleroma rubrum Freitas (2016: 250) , from Bahia. It differs from P. rubrum by the wider leaves (4.7–10.8 cm wide vs. 1.5–4.5 cm in P. rubrum ), inflorescence axes moderately to densely setose (vs. sparsely hirsute) and by the stamens in both cycles with glandulose pedoconnective and appendages (vs. glabrous).

Figures

FIGURE 2. Images of the holotype of Pleroma cucullatum. A. Branch with inflorescence. B. Leaf (adaxial surface). C. Detail of the leaf indumentum (adaxial surface). D. Detail of the leaf indumentum (abaxial surface). E. Bracteoles, variation in size (abaxial surface). F. Dried flower, without petals and sepals. G1. Antesepalous stamen. G2.Antepetalous stamen. H. Gynoecium, apical portion. I. Velatidium. (A–H: Kollmann et al. 10701, I: Goldenberg et al. 1143).

FIGURE 3. Photos of Pleroma cucullatum. A. Natural habitat and habit. B. Branch with inflorescence. C. Bracteoles. D. Detail of the stamens. (Photos A–B by L. Azevedo; C–D by L.J.C. Kollmann).