Eugenia cabofriana T.Fern., Sobral & J.M.A.Braga, 2022

Fernandes, Thiago, Giaretta, Augusto, Sobral, Marcos, Souza, Marcelo Da Costa & Braga, João Marcelo Alvarenga, 2022, Three new species of Eugenia (Myrtaceae) from the Atlantic Forest of southeastern Brazil, Phytotaxa 552 (1), pp. 51-62 : 52-54

1. Eugenia cabofriana T.Fern., Sobral & J.M.A.Braga , sp. nov. Type:— BRAZIL. Rio de Janeiro: Arraial do Cabo, Ilha de Cabo Frio , Vertente N, Mata de Encosta , 22 November 2001, fl., C. Farney, M.O. Souza & J.C. Gomes 4417 (holotype RB00451836 !; isotypes MBML00031556!, RBR00044692!, HUFSJ! [no barcode]) . Figures 1 , 2 and 7 .

Diagnosis:—Morphologically similar to Eugenia prasina O. Berg (1857 –1859: 225; for recent descriptions see Sobral 2011, Valdemarin 2018 and Mazine et al. 2020), differing by the tomentose young shoots (vs. glabrous to puberulent in E. prasina ), blades with acumen 3–5% of the blade’s length (vs. acumen 10–15% of the blade’s length) and pedicels to 1.5–4 mm long, pilose at least when flowers are in bud (vs. 6–26 mm long, always glabrous).

Description:—Tree to 10 m tall and 16 cm diameter at breast height. Stem morphology unknown. Young shoots and leaves tomentose, the trichomes light brown or grey, ca. 0.2 mm, glabrescent; cataphylls (3)6–10 × 1–1.8 mm, narrow elliptic to lanceolate, puberulent.Young twigs slightly applanate, pilose as the young shoots, glabrescent, finely longitudinally striate when mature, drying grey; internodes 10–25 × 1–3 mm. Mature leaves with petioles 9–16 × 1–1.3 mm, glabrous, sulcate adaxially; blades 65–101 × 27–43 mm, 2–2.5 times longer than wide, elliptic, base cuneate, apex acute to acuminate in 2.5–5 mm, chartaceous, discolorous, adaxially shining dark olive-green or brown, abaxially dull light brown, glabrous or with very scattered trichomes persisting especially abaxially; glandular dots 20–30/mm², of distinct sizes, the larger ones to 0.1 mm in diameter, visible only in the abaxial surface; midvein adaxially sulcate at least along the proximal half of the blade, becoming finely impressed or plane towards the apex, abaxially raised and lighter than the surface; lateral veins 12–16 at each side, leaving the midvein at angles about 60°, finely raised on both surfaces, more evidently abaxially; secondary lateral veins and higher order venation evident on both surfaces; intramarginal vein 1.5–2 mm from the margin, the margin itself slightly revolute and with a brownish girdle to 0.2 mm wide. Inflorescences axillary, fasciculiform, with 1–4 flowers, the main axis to 2 × 2 mm or absent, with rufescent trichomes to 0.1 mm; bracts ca. 1 × 1.5 mm, glabrous, hemispheric, deciduous at anthesis; pedicels 1.5–4 × 1 mm, semi-cylindric, densely covered by an arachnoid indumentum, the trichomes to 0.1 mm; bracteoles 2–2.5 × 2.5 mm, triangular, apex acuminate, both surfaces glabrous and margins with scattered cilia to 0.1 mm, free from each other, persisting at anthesis. Flower buds 6–8 × 5–7 mm, obpyriform, the ovary pilose as the pedicels, contrasting with the sepals, these four, glabrous, widely ovate to hemispheric, in two unequal pairs, the outer ones to 3 × 4 mm, the inner ones 4–6 × 4–7 mm, drying dark brown, densely glandular, the margin with a yellowish girdle 0.3–0.5 mm wide, with cilia ca. 0.1 mm; petals ca. 8 × 5 mm, four, glabrous, elliptic, apex rounded; staminal ring ca. 4 mm in diameter, glabrous, stamens and style not measured at early stages of development in the flower buds; calyx tube absent; ovary with two internally glabrous locules, 6–7 ovules per locule. Fruits not seen.

Etymology —The specific epithet refers to the place where the type was collected at the Cabo Frio Center of Plant Diversity (see Araújo 1997).

Distribution, habitat and phenology:—Presently known from a single collection from an island near the coast of Arraial do Cabo, a municipality in the southeastern Brazilian state of Rio de Janeiro ( Figure 7 ). The island is covered with semideciduous forest. Flower buds were collected in late November.

Preliminary conservation status:—Data Deficient (DD) considering that only a single collection is known from the locality, and no additional information is available. The Cabo Frio Island is part of the Cabo Frio Center of Plant Diversity, a region with high level of plant endemism that is also the type locality of several recently described plant species (see e.g., Araújo 1997, Tatagiba et al. 2004, Vianna Filho & Alves 2010, Faria et al. 2015). Thus, it is well possible that E. cabofriana might be endemic from this region. The Cabo Frio Island is under the control of the Brazilian navy, but touristic activities are still allowed and represent the main current threat to the habitat. A reassessment is highly desirable if further data are available in the future.

Affinities:—Beyond the diagnosis, Eugenia cabofriana can also be further compared with E. angelyana Mattos (1989: 2) from southern Brazil, from which it differs by the size of its blades 65–101 × 27–43 mm (vs. blades 35–55 × 12–30 mm in E. angelyana ), flowers with bracteoles persisting at anthesis (vs. deciduous before anthesis), ovary longitudinally smooth (vs. longitudinally costate) and sepals in two unequal pairs, the outer ones ca. 3 × 4 mm, the inner ones 4–6 × 4–7 mm (vs. sepals of the same size, ca. 6 × 3 mm). It shares morphological similarities with Eugenia ochracea Valdemarin & Mazine (in Valdemarin et al. 2019), differing by the tomentose indumentum (vs. floccose in E. ochracea ), flower buds obpyriform with up to 7 mm in diameter (vs. globose, 7.5–9 mm in diameter), bracteoles triangular (vs. lanceolate to linear), and ovaries with 6–7 ovules per locule (vs. 16–22).

Considering the inflorescence morphology, Eugenia cabofriana may be assigned to E. sect. Umbellatae O. Berg (1855 –1856: 204), according the sectional classification proposed by Mazine et al. (2016: 231).

Figures

FIGURE 1. Holotype of Eugenia cabofriana (image provided by and reproduced with the consent of the RB herbarium).

FIGURE 2. Morphology ofEugenia cabofriana.A.Youngshoot.B. Detailof the indumentum on ayoung leaf.C. Detailof aninflorescence. All from the holotype.

FIGURE 7. Map with the presently known occurrence points of the new taxa. Dark lines represent the limits between the Brazilian States.