Eugenia breviacuminata M.A.D.Souza & Sobral, 2018

Souza, Maria Anália Duarte De & Sobral, Marcos, 2018, Six new Eugenia (Myrtaceae) from Amazonas, Brazil, Phytotaxa 349 (1), pp. 18-30 : 18-20

1. Eugenia breviacuminata M.A.D.Souza & Sobral , sp. nov.

Type:— BRAZIL. Amazonas: Manaus, estrada Manaus-Caracaraí, BR-174, km 57 , 15 September 1977, C.D.A. Mota 659 (holotype INPA!) . Figure 1 .

Diagnosis:—This species is related to Eugenia brownsbergii , from which it differs by its blades with more lateral veins (15 to 18 versus up to 12 in E. brownsbergii ) and inner marginal closer to the margin (occupying 9–12% of the distance between the margin and the midvein vs. 19–24% of it), calyx lobes in two unequal pairs (versus about the same size), these and the hypanthium uniformly pilose (versus hypanthium more pilose than the lobes) and ovaries with 40 or more ovules per locule (vs. about 10).

Description:—Trees 11–15 m, about 20 cm in diameter at body height. Twigs applanate, brown, with trichomes to 0.1 mm, these becoming scattered with age and then the twigs turning grey, longitudinally striate. Leaves with petioles semiterete, strongly applanate or sulcate adaxially, 6–10 × 1.5–2 mm, drying black, glabrous or with scattered trichomes as the twigs; blades narrowly elliptic or elliptic, 95–150 × 44–50 mm, 1.9–3 times longer than wide, discolorous when dry, brown, glabrous and somewhat shining adaxially, light brown, ochraceous or greyish, densely and uniformly covered by appressed or curly rufescent trichomes shorter than 0.1 mm abaxially; glandular dots not visible on both faces nor when backlit; base cuneate; apex shortly and sharply acuminate in 4–6 mm; midvein impressed adaxially and raised abaxially; lateral veins 15 to 18 at each side, leaving the midveind and angles 45–60°, finely raised adaxially, a little more so abaxially; secondary lateral veins visible, with a smaller gauge than the main ones; marginal veins two, the inner one about the same gauge as the main lateral veins, the outer one thinner and less perceptible, respectively 2–3 mm and 0.5–0.6 mm from the revolute margin. Inflorescences axillary or ramiflorous, racemiform, the axis 5–12 × 1–1.2 mm, with rufescent ascending trichomes to 0.1 mm, with 4 to 8 flowers; bracts elliptic, 1–1.2 × 0.7 mm, pilose as the axes, persisting; pedicels 7–12 × 0.4–0.5 mm, with trichomes as the axis; bracteoles oblate, 1–1.2 × 1.5 mm, persisting after anthesis, with trichomes to 0.1 mm at the distal portion of the abaxial side; flower buds not seen; hypanthium to 2 mm, densely covered with simple, densely appressed, rufescent trichomes to 0.1 mm; calyx lobes four, glabrous abaxially and with scattered trichomes as the hypathium abaxially, in two widely elliptic, unequal pairs, the shorter ones 1.1 × 2 mm, the larger ones to 3 × 3 mm; petals not seen; stamens not counted, the filaments to 4 mm, the anthers elliptic, to 0.3 × 0.2 mm, occasionally with one apical gland; staminal ring to 2.5 mm in diameter, with trichomes to 0.1 mm; calyx tube absent; style to 6.5 mm, glabrous, the stigma punctiform; ovary with two glabrous locules and 40 to 45 ovules per locule. Fruits not seen.

Distribution, habitat and phenology:—This species is known from two collections from upland forests (“terra firme”) in the municipality of Manaus; flowers were collected in September and December; flowers are described in type’s label as yellow.

Conservation:—Considering that the municipality of Manaus is the most sampled place in the state of Amazonas, with about 96000 collections ( CRIA 2017) in an area of 11400 km ² ( IBGE 2017), resulting in an average of more than 8 collections/km², the fact that this species was collected only twice may be an indicative of its rareness. Nevertheless, in the absence of recent collections and additional information, we suggest scoring this species as DD (Data Deficient) according to IUCN conservation criteria ( IUCN 2001).

Affinities:—This species is related on morphological grounds to E. brownsbergii Amshoff (1950: 14 ; type images C 10015618, MICH 1287708), a species from French Guiana, Suriname and northern Brazil, from which it is distinguished in the diagnosis. The morphology of the inflorescences, with pedicels more than four times longer than the axis internodes, suggest its inclusion in section Umbellatae O. Berg (1855 –1856: 204), according to the phylogenetic scheme proposed by Mazine et al. (2016).

Etymology:—The epithet is allusive to the short acumen of the blades of the species.

Paratype:— BRAZIL. Amazonas: Manaus, estrada Manaus-Caracaraí, km 21 , 28 December 1986, G.T. Prance, B.S. Pena & J.F. Ramos 3835 ( INPA!, K, NY) .

Figures

FIGURE 1. Eugenia breviacuminata (holotype).