Calyptranthes serrana A.R.Lourenço, 2014

Lourenço, Ana Raquel & Alves, Marccus, 2014, A new species and a new geographical record of Calyptranthes (Myrcia s. l., Myrtaceae) from Brazil, Phytotaxa 188 (5), pp. 275-281 : 276-279

Calyptranthes serrana A.R.Lourenço , sp. nov. ( Figures 1–2 .)

Type:— BRAZIL. São Paulo, [Santo André]: Alto da Serra, Estação Biológica , [Reserva Biológica Alto da Serra de Paranapiacaba, 23º46’00’’– 23º47’10’’S and 46º18’20’’S – 46º20’40’’W], 12 December 1928, bt., fl., C. Lemos s.n. (holotype: SPF 67445!; isotypes: SPF 71687!; BHCB 109894 -image) .

Related to C. grandifolia , but differs by having orbicular leaf blades, with abruptly acuminate apices, and 6–7 mm long buds; to C. dryadica but differs by having coriaceous leaf blades, inflorescences 10–11 cm long, three to four lateral branches, and flower buds with rounded apices; and to C. lucida , differing by the inflorescences and buds length, as well as the brownish color of the leaves when dried.

Trees to 5 m, essentially glabrous except for pubescent and ferruginous flower buds; hairs simple, ferruginous. Leaf blade orbicular to orbicular-elliptic, 9–10.5× 6.5–7 cm, coriaceous, brownish when dried, concolorous; apex abruptly acuminate; base rounded and attenuate; margin slightly revolute; midvein sulcate above, prominent below; secondary veins barely visible on both surfaces, impressed above, slightly prominent below; marginal vein 3–4 mm from margin; intramarginal vein up to 1 mm from margin; glandular dots not visible on both surfaces; petiole 1.5–2 cm long, 2.5–3 mm wide. Inflorescence of terminal paired panicles 10–11 cm long, axes compressed to terete, three to four lateral branches, these subopposite to alternate, slightly arched, ca. 15–25 flowers per panicle; basal bracts deltoid, 1× 1 mm, caducous; peduncle 5.5–6 cm long; bracts caducous, not seen; flowers sessile; bracteoles deltoid to linear, up to 1 mm long, caducous; flower buds obovoid, slightly constricted between the hypanthium and calyptra, slightly pyriform, 6–7× 3–6 mm, apex rounded, with a very shortly apiculate calyptra; hypanthium prolonged up to 1 mm beyond ovary, internally glabrous; petals absent; stamens ca. 120, filaments 6–8 mm long, anthers up to 0.5 mm long, ellipsoid; style 6–8 mm long, stigma punctiform; ovary bilocular to trilocular, with two to four ovules per locule. Fruits not seen.

Distribution and habitat:—The species is restricted to São Paulo state thus far, where samples from three areas were located in the visited herbaria, all sharing environmental conditions such as vegetation type and altitude. The “Reserva Biológica Alto da Serra de Paranapiacaba” (RBASP) is a Brazilian conservation unit (UC) comprising about 440 ha located in the municipality of Santo André, at 750–900 m elevation ( Pastore et al. 2012). According to Veloso et al. (1991) the predominant vegetation type is “Floresta Ombrófila Densa Montana ” (Montane Atlantic Forest) composed of distinct physiognomies; however, lack of information prevents assertion of exactly in which physiognomy this species occurs. The UC Estação Biológica de Boracéia (EBB) is located near the city of Salesópolis, São Paulo state, an area with 96 ha of Montane Atlantic Forest, about 100 km from the RBASP ( Ferro & Diniz 2007). Another area where the species was found is part of “Parque Estadual da Serra do Mar”, also a UC with ca. 310.000 ha, located at the Serra do Mar corridor, the fourth area with the highest endemic angiosperm richness in the Brazilian Atlantic rainforest (Werneck et al. 2011). The three areas are distant 100–200 km from each other, which clearly shows that C. serrana has a restricted occurrence area as well as habitat of occurrence.

Conservation status:—In a herbarium based survey on collections made between 1983–1995 to recollect species represented only by very old collections, Kirizawa et al. (2009) listed 68 species of Myrtaceae in the RBASP (the second most species-rich family, only preceded by Orchidaceae ). Since 1970, the area has been subject to the continuous action of pollutants due to its proximity to the Cubatão chemical pole ( Kirizawa et al. 2009). The site is also disturbed by the presence of numerous invasive plants and logging of timber species ( Pastore et al. 2012). After the first collection dated 1928, the species was collected again in 1967, Salesópolis, and subsequently after 34 years, in São Luis do Paraitinga. Although the areas in which the species where be found are inserted in UC’s, following the IUCN (2010) red list criteria, we here assign C. serrana to the endangered category (EN), based on the criteria: B2ab(ii) (area of occupancy <500 km 2, number of locations ≤ 5 and a continuing decline in area of occupancy) and D (very small or restricted population).

Etymology:—The epithet refers to the type locality (Alto da Serra de Paranapiacaba).

Affinities and discussion:—Among other species of Calyptranthes from the Atlantic rainforest of São Paulo, C. serrana could be confused with C. grandifolia O. Berg (1857: 48) , C. dryadica M.L. Kawasaki (1998: 386) and C. lucida Martius ex De Candolle (1828: 258) ( Table 1). Calyptranthes serrana can be distinguished from C. dryadica mainly by its orbicular and coriaceous leaf blades (vs. widely elliptic to elliptic), flower buds with rounded apex (vs. apiculate) and inflorescences 10–11 cm long (vs. 3–8 cm long). Calyptranthes grandifolia is a widely distributed species, with remarkable morphological plasticity. Despite this variation, some features are very distinct from C. serrana such as the elliptic to lanceolate-elliptic leaf blades with acute to acuminate (vs. abruptly acuminate in C. serrana ) apices and 3–5 mm long buds. Another widespread species with remarkable plasticity is C. lucida , which can be distinct from C. serrana also by the inflorescences size (10–11 cm long vs. 4–5.6 cm), the flowers buds size (6–7 mm long vs. 1–3 mm) and by the colour when dried (brownish vs. greenish).

The ovary in Calyptranthes is mainly described in the literature as bilocular with two ovules per locule, with the exception of Landrum & Kawasaki (1997), who state that it can be 2(–3)-locular. In the ongoing taxonomic review for the Atlantic Rainforest domain, several species with trilocular ovary and variable numbers of ovules per locule were observed; C. serrana is one of them. The consistency of this character as diagnostic is questionable however, as it appears to vary among individuals of the same species.

Some recently described species of Calyptranthes match the observation of Joppa et al. (2011), that many species published as new in recent years are described based on just a few herbarium collections, indicating that the remaining species to be described are probably narrow endemics. Calyptranthes fusiformis M.L.Kawasaki ( Kawasaki 1996) , C. boanova Sobral , C. curta Sobral & O. Aguiar , C. detecta Sobral & M. Souza and C. maritima Sobral & Bertoncelo ( Sobral et al. 2012) , C. santalucia Sobral ( Sobral 2013) and now C. serrana are some examples. These species are clearly rare and their limited occurrence in the field may explain a lack of samples in herbaria.

There is a considerable lag time between the three known collections of C. serrana . This time is even longer, considering the first collection (1927) and its publication as a new species. This time lapse is close to recently published estimates of the average time that species remain undescribed after the first collection ( Bebber et al. 2010) and suggests global taxonomic capacity to describe new species of flowering plants is stagnant at a time of unprecedented concern for conservation and extinction ( Bebber et al. 2010; 2013).

Paratypes:— Brazil. São Paulo, Salesópolis: Estação Biológica de Boracéia [23º37’59’’S – 45º31’59’’W], perto do Rio Corujá , 29 November 1967, bt., fl., J. Mattos & N. Mattos 14272 ( SP 157928!; UFP 77550!); São Luis do Paraitinga [23º20’66’’S– 45º07’30’’W], Núcleo Santa Virgínia , trilha do Rio Ipiranga , 21 November 2001, bt., Disciplina Princípios e Métodos em Taxonomia Vegetal 46 ( HRCB, BHCB-images) .

Figures

FIGURE 1. Calyptranthes serrana (A) fertile branch, (B) detail of the inflorescence (panicle) showing the branching pattern, some branches slightly arched (C) Flower bud with a rounded apex, slightly constricted between the hypanthium and calyptra (D) Flower (E) Leaf blade; adaxial surface. Illustration by Regina Carvalho, drawn from the holotype.