Myrcia ubatubana Mazine & Sobral 2016, sp. nov.
Creators: name: Sobral, Marcos
name: Caliari, Cláudia P.
name: Gressler, Eliana
name: Mazine, Fiorella F.
name: Magenta, Mara
name: Viana, Pedro L.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Myrtaceae
Myrcia
Myrcia ubatubana

description: 6. Myrcia ubatubana Mazine & Sobral, sp. nov.
Type:— BRAZIL. São Paulo: mun. Ubatuba, Parque Estadual da Serra do Mar, -23.4339, -45.0711, 800 m, 13 April 2011, A.C.O. Souza, L.C. Bernacci & R. Belinelo s.n. (holotype IAC 53476!; isotype HUFSJ!). Figure 8.
This species is related to Myrcia ferruginosa, from which it is distinguished by its pauciflorous (up to nine flowers versus 20 or more in M. ferruginosa), less ramified inflorescences (one level of branching versus two or more) and narrower blades (to 4–5.5 times longer than wide vs. 2.5–3 times longer than wide).
Trees 11– 17 m. Twigs densely covered with rufescent simple trichomes to 1 mm; internodes subterete, 35–50 × 2 mm. Leaves with petioles 4–7 × 1.2–2 mm, more or less pilose, adaxially sulcate; blades lanceolate to narrowly lanceolate, 115–170 × 21–40 mm, 4–5.5 times longer than wide, discolorous when dry, dull green adaxially and yellowbrown abaxially, mostly glabrous adaxially or with trichomes along the midvein, more or less densely pilose abaxially, with rufescent appressed trichomes to 1 mm, these becoming more sparse with age but usually persisting along the midvein; glandular dots to 0.1 mm in diameter, 10 to 15/mm², usually coinciding with the areolae, visible adaxially; apex acuminate in 15–20 mm; base widely cuneate or obtuse; midvein impressed adaxially and raised abaxially; lateral veins 40 to 50 at each side, leaving the midvein at angles 80–85º, slightly raised on both sides; marginal vein about 1 mm from the margin, sometimes a second vein 0.5 mm from the margin, the margin itself recurved. Inflorescences paniculiform, 45–50 × 1–1.2 mm, the peduncle 22–30 × 1.2 mm, with one branch to 6 mm, with about nine sessile flowers in three clusters at the tip of the branches; bracts widely triangular, to 5 × 4 mm, with rufescent trichomes to 0.5 mm abaxially; bracteoles two, concealing the flower buds, ovate or elliptic, 5 × 3–4 mm, pilose abaxially as the bracts; flower buds elliptic, to 5 × 4 mm, with calyx lobes mostly fused and hardly distinguishable, tearing at anthesis in four or five irregularly triangular pieces 1.5–2.5 × 3–3.5 mm; petals 3 to 4, rounded or obovate, glabrous, to 2.5 × 2 mm; stamens about 90, filaments 6–7 mm, the anthers elliptic, 0.4 × 0.3 mm, with one subapical gland; staminal ring 3 mm in diameter, glabrous; calyx tube 2 mm deep, glabrous; style 10 mm, glabrous, the stigma slightly capitate and minutely papillose; ovary with two locules and two ovules per locule. Fruits not seen.
Distribution, habitat, phenology:—This species is a tree from northern coastal rainforests of the state of São Paulo, being presently known only from the municipality of Ubatuba; flowers were collected in January, February and April.
Conservation:—The municipality of Ubatuba has been intensely surveyed botanically, since there are registered more than 22,300 gatherings (CRIA 2015) for an area of 723 km ² (IBGE 2015b), with the elevated average of 31 collections/km²; nevertheless, the relative scarcity of collections may be an indicative of the relative rareness of M. ubatubana. So, in the absence of additional information, we suggest that this species be scored as DD (Data Deficient) according to IUCN criteria (IUCN 2001), irrespective of the fact that all collections known are from a protected area, what could suggest that populations of this species are devoid of environmental risks.
Affinities:— Myrcia ubatubana is apparently related to Myrcia ferruginosa Mazine (Mazine et al. 2014: 98; replacement name for Marlierea silvatica (O.Berg) Kiaerskou [Berg 1855 –1856: 81; Kiaerskou 1893: 51; type image: K barcode 000330563]; for description see Legrand & Klein 1971, under this name), from which it is distinguished through the characters given in the diagnosis. The partially closed calyx tearing irregularly at anthesis and the bilocular ovaries of this species suggest its inclusion in the informal “group 2” of the phylogenetic scheme of Myrcia s.l. proposed by Lucas et al. (2011), which comprises some species formerly included in the genus Marlierea Cambessèdes (1832 –1833: 373).
Paratypes:— BRAZIL. São Paulo: mun. Ubatuba, Estação Experimental de Ubatuba—IAC, 31 January 1980, G.J. Shepherd, J.Y. Tamashiro & A.F. Silva (IAC 21209!, UEC); idem, Parque Estadual da Serra do Mar, Núcleo Picinguaba / Instituto Agronômico de Campinas, trilha do Poção, (SAD69, zona 23), 16 February 2005, N.M. Ivanauskas, F.M. Souza, R. Cielo Filho, C.O. Araújo, D. Souza & Sr. Rosendo 6017 (RB!, SPSF); idem, Parque Estadual Serra do Mar, -23.4339, -45.0711, 800 m, 13 April 2011, A.C.O. Souza, L.C. Bernacci & R. Belinelo s.n., (IAC 53477!; HUFSJ!); idem, 22 February 2011, A.C.O. Souza, L.C. Bernacci & R. Belinelo s.n. (IAC 53475!; HUFSJ!); idem, 14 April 2011, A.C.O. Souza, L.C. Bernacci & R. Belinelo s.n. (IAC 53478!; HUFSJ!).
description: Published as part of Sobral, Marcos, Caliari, Cláudia P., Gressler, Eliana, Mazine, Fiorella F., Magenta, Mara & Viana, Pedro L., 2016, Seven new southeastern Brazilian species of Myrcia (Myrtaceae), pp. 27-44 in Phytotaxa 247 (1) on pages 39-41, DOI: 10.11646/phytotaxa.247.1.2, http://zenodo.org/record/13676381