Myrcia rogersiana B. S. Amorim 2018, sp. nov.
Creators: name: Amorim, Bruno S.
name: Alves, Marccus
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Myrtaceae
Myrcia
Myrcia rogersiana

description: Myrcia rogersiana B.S. Amorim sp. nov. (Figures 1, 2 D–F.)
Type:— BRAZIL. Espírito Santo: Mun. Nova Venécia, Área de Proteção Ambiental Pedra do Elefante, 19 February 2008, fl., P.H. Labiak, J.L. Paixão, A.M. Amorim & R.C. Forzza 4712 (holotype: RB!; isotypes: BHCB, CEPEC, HUFSJ, MBML, UFP!, UPCB).
Treelet up to 3 m tall, morphologically closely related to Myrcia springiana (O. Berg) Kiaerskou (1893: 102; basionym: Gomidesia springiana O. Berg, 1857 –1859: 13) but differs by its reduced inflorescence main axis (vs. expanded main axis in M. springiana) and flowers clustered at the apex of the inflorescence (vs. flowers evenly distributed along the inflorescence in M. springiana).
Treelet up to 3 m tall; young stems puberulent, covered by yellowish (when dry), simple trichomes; leaf decussade; leaf blade elliptic, 11–14.5 × 3.6–5.1 cm, flat adaxially, membranaceous (when dry), base cuneate; apex acute; scattered, appressed trichomes (<1 mm long) abaxially and adaxially, strigose; midrib sulcate with puberulent white trichomes (when dry) adaxially; secondary veins in 12–14 pairs, diverging at 70–80º from the midvein, marginal vein 2–3 mm from the margin, inframarginal vein 1 mm from the margin; petiole 4–5 mm long, sulcate adaxially, puberulent. Inflorescence panicule, reduced, main axis 2–3.5 cm long, pubescent, multi-flowered, clustered at the apex of the inflorescence; bracts not seen, deciduous; bracteoles not seen, deciduous; hypanthium smooth, pubescent; calyx lobes-5, 2 mm long, rounded, puberulent (whitish trichomes when dry), petals not seen; stamens ca. 200, filaments 4–5 mm long, brownish (when dry), anthers 1 mm long, elliptic, thecae with displaced opening, septum not visible; staminal ring 3 mm in diameter, puberulent; style 6–7 mm long, basis puberulent, stigma punctiform; hypanthium prolonged 1 mm beyond the ovary; ovary 2-locular with 2-ovules per locule. Fruit not seen.
Affinities:—It is morphologically similar to M. springiana, which share leaf shape features, but differs by its reduced inflorescence main axis 2–3.5 cm long and flowers clustered at the apex of the inflorescence (vs. expanded inflorescence main axis 13–15 cm long, and flowers evenly distributed along the inflorescence in M. springiana). Myrcia rogersiana is also similar to M. anacardiifolia Gardner (1843: 354) and M. gestasiana Cambessèdes (1832: 303), which share leaves with appressed trichomes abaxially, reduced inflorescence with flowers clustered at the apex, and calyx lobes 1–3 mm long, but it differs by leaves with marginal vein distant 2–3 mm from the margin (vs. leaves with marginal vein distant 4–7 mm from the margin in M. anacardiifolia), leaves 11–14.5 cm long and rounded calyx lobes (vs. leaves 7–10 cm long and acute calyx lobes in M. gestasiana); see table 2 for a detailed comparison.
Distribution and habitat:— Myrcia rogersiana is endemic to Brazilian Atlantic Forest and restricted to the northern submontane forests of Espírito Santo state in southeastern Brazil. The southern portion of submontane forests of Espírito Santo state is known due to its high endemism of Myrcia s.l. and Gomidesia clade species (Sobral 2010 b, Amorim & Alves 2016), while the northern portion is historically poorly sampled (see Figure 1). The restrict distribution of Myrcia rogersiana highlights the importance of botanical efforts in poorly known areas and also the submontane and montane forests in Gomidesia clade species diversification (Amorim & Alves 2015, 2016, Amorim 2017).
Phenology:—Flowers in February.
Etymology:—The epithet honours Dr. Rogers McVaugh (1909–2009), who encourage the first author in his first steps on the taxonomy of Myrtaceae and was one of the most important taxonomists of the 20 th century due to his lifelong study of the family.
Conservation status:—This species is known only for the type locality. Due to the high collection efforts and large number of studies in the Atlantic Forest of the Espírito Santo state described, we concluded that Myrcia rogersiana is a rare species with restricted occurrence. Based on that, the species meets the criteria of Vulnerable (VU; criterion D).
description: Published as part of Amorim, Bruno S. & Alves, Marccus, 2018, New narrowly distributed species of Myrcia s. l. (Gomidesia clade, Myrtaceae) from the Atlantic Forest of southeastern Brazil, pp. 182-188 in Phytotaxa 343 (2) on pages 184-186, DOI: 10.11646/phytotaxa.343.2.9, http://zenodo.org/record/13718656