Eugenia marleneae M.A.D.Souza & M.Mendonça, 2015

De Souza, Maria Anália D., Scudeller, Veridiana V. & Mendonça, Maria Sílvia De, 2015, Three new species of Eugenia (Myrtaceae) from Brazilian Amazonia, Phytotaxa 212 (1), pp. 87-94 : 92

3. Eugenia marleneae M.A.D.Souza & M.Mendonça , sp. nov.

Type:— Brazil. Amazonas: Manaus, Reserva Florestal Adolpho Ducke , 02 o 53’S, 59 o 58’W, 21 September 1995, A. Vicentini & C.F. da Silva 1049 (holotype INPA! , isotypes INPA! , SEL! ). Figures 1C–G .

Morphologically similar to Eugenia gomesiana , Eugenia marleneae differ by its orbicular bracteoles (vs. filiform), inflorescence with strigose trichomes (vs. villose), and midvein adaxially concave (vs. prominent), and to Eugenia trinervia , being distinguished from it by its fasciculate inflorescences (vs. racemose) and large pyriform fruits to 55 mm (vs. globose or oblong to 10 mm). Additionally, Eugenia marleneae is distinct from all Amazonian species for its 3–4-locular ovary.

Tree, 15–40 cm diam., 8–25 m high, trunk slightly channeled, rhytidome blotchy, the periderm detaching in leathery, revolute blades to 50 cm long, or orange to brown peel or scars; twigs plannate, strigose, with silver or brown simple trichomes ca. 0.2 mm long. Petiole 6–10 mm, canaliculate, puberulent; leaf blade elliptic to widely elliptic, 70– 95 × 40–53 mm, chartaceous to subcoriaceous, glabrous or with appressed trichomes when young, and with glandular dots slightly prominent on both sides, obscure, the apex acuminate, rarely acute, the base cuneate; midvein concave and the lateral veins salient adaxially, these ascendant to arcuate, the marginal vein simple to double, the intramarginal vein 3–4 mm from the margin, arcuate to semi-arcuate. Inflorescence an axillary to ramiflorous raceme, simple, single to superposed, fasciculate to short-racemose, the peduncle 3–12 mm, uniflorous to biflorous or the peduncle with two pairs of flowers; pedicel 5–15 mm long, densely strigose, trichomes silver to shining brown, the vegetative growth of the shoot continuous above the flowers; bracts persistent, 1.5–4 × 1 mm, orbicular to deltoid, abaxially carenate; bracteoles orbicular, 1.2–2.5 × 1–2 mm, free to connate until about one-third of its length, involucrate, abaxially pilose, margin ciliate; flowers to 20 mm diam., the hypanthium infundibuliform, 2–3 × 1.5–3 mm, lower one-third of the bud, margin not exceeding the top of the ovary, strigose, the globe of bud 8–10 × 5–8 mm, globose to ellipsoid; sepals subequal to unequal, 3–5 × 2–4 mm, orbicular to oblong, the apex rounded, basally connate, abaxially flat to convex and carenate, glabrous to pubescent on both sides, persistent, white to greenish, reflexed; petals oblong to obovate, 7–12 × 4–6 mm, white, imbricate, ciliate; staminal disk quadrangular, 4 mm diam., pubescent; stamens 40–50, filaments filiform, 5–6 mm long; anthers oblong, dorsifixed to basifixed, 0.8–1 mm long, rimose, connective with one apical gland, this impressed to indistinct; style 6–10 mm, glabrous to pubescent at the base, apex greenish, stigma capitate, white; ovary (3–)4-locular, ca. 5 ovules per locule. Fruit pyriform, 30–55 × 20–43 mm, pubescent, fleshy and succulent; seeds ca. 3, suboblong (12 mm high × 10 mm diam.) or laterally flattened with poles appressed (20 × 28 mm wide); testa coriaceous, smooth, the rapheal scar short; cotyledons fused, the hypocotyl indistinct.

Distribution and habitat:— Eugenia marleneae is only known from Amazonas state, in central (municipality of Manaus) and western region (Pico Rondon and municipality of São Paulo de Olivença). It is found in dense humid forests, on terra firme (plateau terrain) and “baixio”, i.e. environment near streams with vegetation on sandy soil.

Phenology:—Buds, flowers and immature fruits were collected from March to September, with ripe fruits collected in December.

Etymology:—The epithet honors the first Amazonian botanist born in Amazonas, Dr. Marlene Freitas da Silva (1937–2005). She contributed greatly to the knowledge of Amazonian plants, to training students in taxonomy and especially in floristic inventory, and in organizing the INPA and UEA herbaria. Dr. Marlene da Silva left a great legacy and she was one of the main collaborators and mentors in studies developed at the Reserva Florestal Adolpho Ducke. Conservation status:—Due to the small numbers of collections in herbaria this species should be scored as Data Deficient (DD) according to IUCN conservation criteria IUCN (2014).

Paratypes:— BRAZIL. Amazonas: Manaus, Distrito Agropecuário, 90 km NE de Manaus, Reserva 150 (km 41) , 02°24’S, 59°43’W, 5 November 1991, A.A. Oliveira et al. 202 ( INPA!) ; Estrada Manaus-Porto Velho, trecho entre os rios Castanhos e Tupana , 14 July 1972, M.F. Silva et al. 752 ( INPA!) ; Estrada AM 10, km 74 ao lado direito , 3 September 1965, W. Rodrigues & A. Loureiro 7095 ( INPA!) ; Pico Rondon, km 211 of Perimetral North Hwy. , 01 o 32’N, 62 o 48’ W, 25 March 1984, J.J. Pipoly et al. 6913 ( INPA!, NY!) ; Reserva Florestal Adolpho Ducke , 02 o 53’S, 59 o 58´W, 13 December 1995, M.A.D. Souza et al. 188 ( INPA!, SEL!) ; São Paulo de Olivença, basin creek Belém , 26 October to 11 December 1936, B.A. Krukoff et al. 8911 ( G!, NY!, RB!) .

Vegetatively E. marleneae is similar to Eugenia trinervia Vahl (1798:36) , which has inflorescence axes essentially elongated and pedicels longer than the intervals between the rachises. Eugenia trinervia also differs from E. marleneae by its small and globose or oblong (ca. 10 mm) fruits, and had been collected in Central America ( Guadalupe, Martinique) only.

Eugenia marleneae , in addition, is too morphologically similar to E. gomesiana O. Berg (1857: 254) , but differs by its fissured to smooth branchelets (vs. suberose), chartaceous elliptic leaves (vs. coriaceous to rigid, and oblong), leaf apex distinctly acuminate (vs. acute) and base distinctly cuneate, respectively (vs. obtuse or acute) and concave midvein. Eugenia marleneae also has orbicular bracteoles (vs. filiform, Figure 1G ), hypanthium infundibuliform (vs. campanulate) and inflorescence with strigose trichomes (vs. villose), and (3-)4 - locular ovary, an uncommon feature in the genus. Eugenia marleneae and E. gomesiana are both deciduous, renewing their foliage during flowering. This feature can create difficulties for identification, since the only visible characters are the shape of the caducous bracteoles and the presence of scaly stipules 0.3–10 mm in the terminal branches of E. gomesiana . Indeed, E. gomesiana is found in cerrado vegetation in Central Brazil and in flooded areas of the Brazilian Amazon only.

Figures

FIGURE 1. A–B. Eugenia caducipetala (drawn from the holotype). A. Flowering branch. B. Flower. Note the absence of petals. C–F. Eugenia marleneae. C. Fruiting branch (Souza et al. 188). D. Detail of paired peduncles, and the continuous vegetative growth of the shoot (drawn from the holotype). E. Flower bud. F. Inflorescence biflorous. Note the scaly bracteole. G. Flower bud of Eugenia gomesiana. Note the filiform bracteoles (Daly et al. 558, INPA).