Eugenia ruschiana, Bünger & Mazine & Stehmann, 2016

Bünger, Mariana De Oliveira, Mazine, Fiorella Fernanda & Stehmann, João Renato, 2016, Eugenia ruschiana (Myrtaceae), a new species from southeastern Brazilian Atlantic forest, Phytotaxa 266 (1), pp. 40-44 : 40-43

Eugenia ruschiana , sp. nov.

TYPE:— BRAZIL. Espírito Santo: Santa Teresa, Reserva Biológica Augusto Ruschi , estrada entre a sede e a represa da divisa com área residencial. 19º54’23’’ S, 40º33’35’’ W, 789 m elev., 04 October 2012, Bünger et al. 618 (holotype BHCB! , isotype K! ). Figures 1–2 .

This species is related to Eugenia itacarensis Mattos (1974: 3) but can be distinguished by the leaves with margins often plane (versus revolute in E. itacarensis ) and with two marginal veins (vs. one), smaller flower buds (to 18 × 14 mmvs. to 26 × 17 mm), flowers with longer pedicels (26–31 mm vs. <22 mm long) and shorter and narrower bracteoles (9–13 mm long and 1–1.3 times longer than wide vs. 17–34 mm long and 1.7–1.9 times longer than wide)and calyx lobes in unequal pairs (vs. four lobes of the same size) and shorter (largest ones to 11 mm long vs.> 15 mm long).

Small tree 5–8 m high; mature twigs subquadrate, glabrous. Leaves with petioles 13–16 × 2.5–3 mm, pubescent, canaliculate; blades oblong, 17.5–19.5 × 4.1–6.5 cm, coriaceous, discolorous in fresh material, concolorous when dry, glabrous except for trichomes in the midvein on both sides, glandular dots not visible adaxially, scarcely visible abaxially; apex acuminate; base acute or attenuate; margin often plane, rarely revolute; midvein sulcate adaxially, raised abaxially; lateral veins 18–30 on each side, visible on both sides; marginal veins two, the inner one 3.6–6 mm from the margin, the outer one to 1.5 mm. Inflorescences auxotelic, terminal, 2–4 flowers; pedicels 26–31 mm long, pubescent; bracts ovate, ca. 5 mm, the apex acute, base cordate, pubescent; bracteoles widely ovate, 9–13 × 9–10 mm, the apex acute or obtuse, pubescent, concealing the ovary at anthesis. Buds obpyriform, 15–18 × 4–14 mm; calyx lobes 4, widely ovate, unequal, the external pair 10–11 × 5.8 – 6 mm, the internal pair 7–9 × 3–4 mm, pubescent on both sides, longer than the globe of the petals in the flower bud; petals 4, 12–13 × 6–8 mm; stamens more than 100; staminal ring, ca. 4 mm in diameter, subquadrate; ovary ca. 3 × 4 mm, covered with densely appressed trichomes, with two locules and several ovules per locule;, style ca. 15 mm long. Fruits not seen.

Distribution:— Eugenia ruschiana is a tree from montane Atlantic rainforest of Espírito Santo state, occurring at altitudes from 250 to 790 m elev.

Phenology:— Flowers were collected in August and October.

Etymology:— The specific epithet pays homage to Augusto Ruschi, who was an important ambientalist in Brazil, and it also refers to the locality were the species was collected, Augusto Ruschi Biological Reserve.

Conservation status:— This new species is known from two collections from the neighboring municipalities of Santa Teresa and Santa Leopoldina ( Figure 2 ), with populations of few individuals in an area with less than 5,000 km 2, since the two municipalities sum an area of 1,400 km 2 ( IBGE 2016). Although the species also occurs in a protected area, forests around the type locality are very fragmented and show a continuing decline in extension, considering that only 18% of the municipality of Santa Teresa retains its original vegetation ( Mendes & Padovan 2000). According to the information mentioned before, Eugenia ruschiana is assessed here as Endangered (EN), fitting criteria B1ab(iii) of the IUCN Red List criteria ( IUCN 2013), being criterion B1 the extent of occurrence of less than 5,000 km ², criterion “a” the occurrence in less than five localities and “b(iii)” a continuing decline in the area and quality of the habitat.

Discussion:— The well developed bracteoles of Eugenia ruschiana place this species in Eugenia section Phyllocalyx (O.Berg) Niedenzu ( Berg 1855 –1856: 306, Niedenzu 1893: 82), a group proposed by Niedenzu to accommodate species previously segregated by Berg in his genus Phyllocalyx . Since the work of Niedenzu the merging of Phyllocalyx in Eugenia has been widely accepted, and the phylogenetic study of Mazine et al. (2014) showed section Phyllocalyx as a monophyletic clade embedded in Eugenia . Eugenia ruschiana is apparently related to E. itacarensis , an Atlantic rainforest species restricted to the southeastern state of Bahia, from which it can be distinguished through the characters cited in the following key:

1. Young and mature twigs subquadrate; blades with margin often plane, green or almost brown adaxially, green abaxially; midvein pilose on both sides; marginal veins two; pedicels longer than 25 mm; bracteoles 9–13 mm long, 1–1.3 times longer than wide; sepals up to 11 mm long; pedicels longer than the bracteoles (ratio pedicel length / bracteole length 2.3–2.9:1); buds obpyriform, to 18 × 14 mm; calyx lobes in two unequal pairs, the longest pair to 11 mm; montane forests from the state of Espírito Santo ....... ......................................................................................................................................................................................... E. ruschiana

- Young twigs subquadrate, mature twings rounded; blades with margin revolute, dark-brown adaxially, yellowish-brownish abaxially; midvein glabrous on both sides; marginal vein one; pedicels to 22 mm; bracteoles 17–34 mm long, 1.7–1.9 times longer than wide; sepals more than 15 mm long; pedicels shorter than the bracteoles (ratio pedicel length / bracteole length 0.7–0.8:1); buds subglobose, to 26 × 17 mm; calyx lobes of equal size, longer than 15 mm; coastal forests from the state of Bahia .......................... ........................................................................................................................................................................................ E. itacarensis

Paratype:— BRAZIL. Espírito Santo: Santa Leopoldina, Fazenda Caioaba , propr. Virloni, mata, trilha da divisa, 20°03’33” S, 40°28’14” W, 250–500 m, 09 August 2006, L.F.S. Magnago et al. 1248 ( BHCB!, MBML!) .

Figures

FIGURE 1. Eugenia ruschiana. Holotype (Bünger et al. 618, BHCB).

FIGURE 2. Map of distribution of Eugenia ruschiana.