Myrcia costeira M.F.Santos, 2015

Santos, Matheus F., Lucas, Eve & Sano, Paulo T., 2015, Five new South American species of Myrcia s. l. (Myrtaceae), Phytotaxa 234 (2), pp. 159-171 : 165-166

3. Myrcia costeira M.F.Santos , sp. nov. ( Figs. 2 , 3E–J )

Myrcia costeira is related to Myrcia bicarinata ( Berg 1857: 118) Legrand (1961: 298) , but differs in the cataphyll that occur at all internodes (vs. usually only at the basal internode), leaf blades 2.1–5.4 cm long (vs. 4.5–9.4 cm long), venation that is usually inconspicuous on the abaxial surface (vs. usually conspicuous) and the inflorescence with terminal dichasia bearing three flowers (vs. lateral flowers reduced and only the central flower developed).

Type:— BRAZIL. Paraná: Mun. Guaraqueçaba, rio Murato, 7 December 1972 (fl.), G. Hatschbach 31837 (holotype MBM!, isotypes C!, K!, G!, NY!, SP!).

Tree 2– 12 m. Epidermal peeling present in immature parts; trichome light brown (rarely ferruginous), 0.1–0.2 mm long, dibrachiate. Twig when immature reddish or stramineous, flattened, keeled, puberulent or with scattered trichomes to glabrous; mature twig greyish, cylindrical, cortex slightly cracked, glabrescent to glabrous; branching monopodial or sympodial, 2–3 branches per node (rarely more than three), epidermal protrusion present in the internodes only when branching is sympodial, internode 1–3 cm long; cataphyll scale-like to foliaceous, 2–8 × 1–2 mm, present at all internodes (sometimes only at the basal one), early deciduous, free, lanceolate or ovate, with scattered trichomes externally, glabrous internally; branch with 1–2 apical buds, puberulent or with scattered trichomes. Leaf concolorous, chartaceous, blade 2.1–5.4 × 0.9–2.7 cm, elliptic or obovate, apex acute, obtuse or rounded, base cuneate or obtuse, margin sometimes slightly revolute at the base, secondary veins 2.0– 4.5 mm apart, held at an angle of 55–75 o relative to the midvein, marginal vein 0.5–1.0 mm from the margin, tertiary veins slightly conspicuous to inconspicuous; adaxial surface glabrous, midvein sulcate in the first half and flat in the second half, secondary veins inconspicuous (rarely prominent), pellucid dots conspicuous to inconspicuous, less than 5 to more than 15 per mm 2; immature abaxial surface with scattered trichomes, glabrous at maturity, midvein prominent, secondary veins slightly prominent or inconspicuous, pellucid dots conspicuous to inconspicuous, less than 5 to more than 15 per mm 2; petiole 2–5 × 1–2 mm, canaliculate, with scattered trichomes to glabrous when immature, glabrescent to glabrous at maturity. Panicle 2.0–5.5 × 1.0– 3.5 cm, corymbiform (rarely pyramidal), terminal axillary or subterminal, 10–40 flowers, rachis puberulent to glabrous, branching 1–6 times at the base (sometimes including vegetative branches), first internode of central rachis 1–2 mm wide, flattened, distal internodes flattened, opposite branching (rarely subopposite), 2–3 branches per node, epidermal protrusion present at internodes, usually absent in apical branches. Bract 0.6–1.2 × 0.4–0.8 mm, deciduous, lanceolate or ovate, concave, apex acuminate, base truncate, adaxial surface with scattered trichomes to glabrous, abaxial surface puberulent to glabrous. Pedicel 0–2.4 mm long, cylindrical, with scattered trichomes to glabrous. Bracteole 0.6–1.2 × 0.2–0.4 mm, deciduous, lanceolate or ovate, concave, apex acuminate, base truncate, adaxial and abaxial surfaces glabrous. Floral bud 2–4 × 1–2 mm, turbinate. Hypanthium extending 0.8–1.2 mm above the summit of the ovary, not tearing at anthesis, glabrous externally, pellucid dots conspicuous, covering the whole surface, glabrous internally; calyx 4–5-merous, lobes 0.4–1.2 × 0.8–2.0 mm, distinct from the hypanthium, external lobes smaller than internal lobes, deciduous, depressed ovate, concave, apex rounded, base truncate, externally with scattered trichomes to glabrous, internally puberulent to glabrous; corolla 5-merous, petal light brown to white, 1.0–2.2 × 1.2–2.4 mm, depressed ovate, widely depressed ovate or very widely ovate, concave, apex rounded, base truncate, externally puberulent or with scattered trichomes to glabrous, internally puberulent or with scattered trichomes to glabrous; staminal ring 0.2 mm wide, glabrous, 49–74 stamens, filament 1.8–4.4 mm long, glabrous, anther 0.24–0.48 × 0.24–0.40 mm, square, oblong or transversely oblong; ovary 0.8–1.0 × 0.8 mm, 2-locular, each locule with two ovules, style 5.0– 7.2 mm long, glabrous, stigma punctiform, papillose. Fruit green when immature, vinaceous at maturity, 4–10 × 4–10 mm, depressed globose or globose, glabrous, pellucid dots covering the whole surface, remnants of calyx lobes present or not; seeds 1–3.

Distribution and Habitat:—The species inhabits forest in restinga and rarely, lowland rainforest (close to restinga forest). Myrcia costeira occurs from the central coast of São Paulo state to the northern coast of Rio Grande do Sul state.

Phenology:—The flowering of Myrcia costeira is from October to December. It presents fruits from November to February, from April to June and in September.

Etymology:—The epithet refers to the distribution of Myrcia costeira , which occurs in coastal forests, sometimes called “mata costeira” in Portuguese.

Conservation status:— Myrcia costeira is restricted to coastal areas under strong pressure from urbanization. Moreover, the species has an area of occupancy smaller than 2,000 km 2 and is just recorded from protected areas in São Paulo state. Myrcia costeira is therefore classified as Vulnerable (VU, criteria B2a, biii; IUCN 2001).

Discussion:— Myrcia costeira has flattened and keeled immature twigs that resemble those of Myrcia bicarinata , a species within which it was previously treated (e.g., Legrand 1961). As described above, M. costeira differs from M. bicarinata in the presence of cataphyll scars at all internodes, usually smaller blades, usually inconspicuous venation on the abaxial surface and, especially, the inflorescence with 3-flowered terminal dichasia. The two species have distinct habitat and distribution patterns. Myrcia costeira is found in forests in restinga from São Paulo state to Rio Grande do Sul, while M. bicarinata occurs in inland semideciduous forest in central-southeastern Brazil (including Distrito Federal, Rio de Janeiro, Minas Gerais and São Paulo states—never in coastal areas).

Paratypes:— BRAZIL. Rio Grande do Sul: Mun. Passo de Torres, February 1987 (fr.), K. Hagelund s.n. (F 2078543!). Mun. Torres , May 1988 (fr.), J.L. Waechter 2330 ( ICN!) ; 28 December 1975 (fr.), O.R. Camargo 657 (F!). Santa Catarina: Mun. Araquarí , 4 m, 12 June 1953 (fr.), R. Reitz 782 ( HBR!). Mun. Barra do Sul, 5 m, 8 April 1953 (fr.), R. Reitz 502 ( HBR!). Mun. Florianópolis, Ilha de Santa Catarina, 11 December 1984 (st.), J. Mattos 27184 (R!). Mun. Garopaba, 15 July 2006 (st.), R. Hentschel s.n. (ICN 157993!). Mun. Sombrio, 10 m, 5 September 1959 (fr.), R. Reitz 9056 ( HBR!) ; 10 m, 31 October 1959 (fl.), R. Reitz 9324 ( HBR!). São Paulo: Mun. Cananéia, Ilha do Cardoso , 14 November 1979 (fl.), D.A. Grande 346 ( SPF!) ; Ilha do Cardoso , 10 May 1990 (fr.), F. Barros 1848 ( SPF!) ; Ilha do Cardoso , 300 m, 3 August 1990 (fr.), P. Martuscelli 1066 ( SP!) ; Ilha do Cardoso , 24 January 2003 (st.), E.J. Lucas 67 (K!) ; Ilha do Cardoso , 9 December 2003 (fl.), E.R. Castro 313 ( HRCB!) ; Ilha do Cardoso , 13 June 1987 (fr.), F. Barros 1368 ( SP!) ; Parque Estadual da Ilha do Cardoso , 25 February 2003 (fr.), V.C. Souza 29024 ( ESA!) ; Parque Estadual da Ilha do Cardoso , 16 November 2012 (fl., fr.), M.F. Santos 851 ( SPF!) ; Parque Estadual da Ilha do Cardoso , 26 June 2004 (fr.), E.R. Castro 377 ( HRCB!) ; Parque Estadual da Ilha do Cardoso , 8 December 2002 (fl.), F.F. Mazine 750 ( BHCB!) ; Parque Estadual da Ilha do Cardoso , 12 November 2004 (fl.), M.P. Sandrini s.n. (SPF 166672!) ; Parque Estadual da Ilha do Cardoso , 24 November 1988 (fl.), M. Kirizawa 2117 ( SP!) ; Parque Estadual da Ilha do Cardoso , 10 December 1987 (fl.), M. Kirizawa 2023 ( SP!) ; Parque Estadual da Ilha do Cardoso , 5 m, 47 o 54’75’’S, 25 o 3’88’’W, 21 May 2006 (fr.), V.G. Staggemeier 81 ( HRCB!) ; Parque Estadual da Ilha do Cardoso , 27 November 1990 (fl.), M. Sugiyama 868 ( MBM!) ; Estação Ecológica Juréia-Itatins, 22 November 1990 (fl.), E.L.M. Catharino 1541 ( SP!). Mun. Ilha Comprida, 3 June 2000 (fr.), P.G. Carrasco 160 ( ESA!). Mun. Pariquera-Açu , Parque Estadual da Campina do Encantado , 28 May 1999 (fr.), M. Sztutman 313 ( ESA!) ; Parque Estadual do Pariquera-Abaixo, 10 January 1999 (fr.), J.R.L. Godoy 47 ( SP!). Mun. Santos, Distrito de Bertioga , 28 November 1989 (fl.), Grupo B 22779 ( UEC!) .

Figures

FIGURE 2. Species distributions. Myrcia ascendens=star; Myrcia attenuata=triangle; Myrcia costeira=circle; Myrcia rupestris=square; Myrcia subterminalis=diamond.

FIGURE 3. Myrcia attenuata. A. habit. B. detail of keeled twig. C. flower at anthesis. D. fruit with attenuate base and remnants of calyx lobes. Myrcia costeira. E. habit. F. detail of keeled twig. G. detail of inflorescence with opposite branching and terminal dichasia. H. floral bud. I. longitudinal section of ovary showing two locules. J. fruit without calyx lobe remnants. Vouchers:A. Granville 6503 (U); B and D. Oldeman T-650 (P); C. Granville 6503 (B); E–I. Hatschbach 31837 (SP); J. Barros 1848 (SPF).