Six new species of Eugenia (Myrtaceae) from Amazonian Brazil Author Souza, Maria Anália Duarte De Author Sobral, Marcos Author Amorim, Gabriela text Phytotaxa 2022 2022-02-28 536 3 197 212 journal article 20330 10.11646/phytotaxa.536.3.1 aa47eed7-8189-4944-9229-fcdc9af730f7 1179-3163 6331824 2. Eugenia humaitana Sobral & M.A.D.Souza , sp. nov. Type :— BRAZIL . Amazonas : Humaitá , rodovia do estanho, a 150 km de Humaitá , 8 o 7.5’ S , 61 o 49’ W , 25 September 1979 , G. Vieira , J. Zarucchi , A.S.L. Silva , C.D.A. Mota & O.P. Monteiro 145 (INPA!, holotype ; isotypes RB!, MO, NY, US). Figures 2 , 3 . Diagnosis:—This species is morphologically related to Eugenia cribrata McVaugh (1969: 174 ; image F 0065132F), but differs by its elliptic blades 47–76 × 18–36 mm , 2–2.6 times longer than wide ( versus narrowly elliptic blades, 66–111 × 22–44 mm , 2.5–3 times longer than wide in E. cribrata ), with acute or slightly acuminate apex, the acumen 3–5% of the blade’s length ( vs . visibly acuminate, the acumen 10–17% of the blade’s length), glabrous bracts, pedicels and flowers ( vs . pilose), pedicels 2.5–5 × 0.5–0.6 mm ( vs . 15–20 × 0.5 mm ) and sepals in two unequal pairs ( vs . about the same size); it may also resemble Eugenia egensis De Candolle (1828: 281 ; for additional description see McVaugh 1958: 695 ; type image M 0137682), but differs by its concolorous or slightly discolorous blades ( vs . visibly discolorous in E. egensis ), 2–2.6 times longer than wide ( vs . 2.5–3.5 times longer than wide), with apex acuminate to 3–5% of the blade’s length ( vs . acuminate to 10–25% of the blade’s length), with glandular dots 3 to 8/mm², these of unequal size, the larger ones to 0.2 mm in diameter ( vs . glandular dots 20 to 30/mm², these about the same size and smaller than 0.1 mm in diameter), intramarginal vein 2–4 mm from the margin ( vs . 0.5–1 mm ), inflorescences fasciculiform, without a developed axis ( vs . racemiform, with an axis 3–20 mm long), pedicels 2–5 × 0.5–0.6 mm ( vs . 10–15 × 0.1–0.2 mm ) and sepals in two unequal pairs ( vs . about the same size). FIGURE 3. Eugenia humaitana . Detail of blade with marked glandular dots (left) when compared with E. egensis (right; specimen of E. egensis : A.R. Lourenço 379 , INPA!). Scale = 5 mm. Description:—Shrub to 2 m . Plants glabrous except for scattered rufescent cilia 0.1–0.2 mm in the bracteoles and sepals. Twigs glabrous, applanate, drying light grey; internodes 17–35 × 1–2 mm . Leaves with petioles semiterete, adaxially applanate, black when dry, 4–6 × 1.7–2 mm ; blades elliptic or slightly elliptic–obovate, 47–76 × 18–36 mm , 2–2.6 times longer than wide, concolorous or slightly discolorous, adaxially dull dark brown or blackish when dry, sometimes lighter abaxially; base cuneate; apex acute or acuminate in 2–4 mm ; glandular dots 3–8/mm², in two or more distinct sizes, the larger ones to 0.2 mm in diameter, black when dry, visible and raised on both sides, more visibly so abaxially; midvein adaxially biconvex, occasionally becoming flat in older blades, abaxially strongly raised; lateral veins 8–9 at each side, leaving the midvein at angles 60–70°, finely raised adaxially and more visibly so abaxially, secondary lateral veins and higher order venation occasionally perceptible; intramarginal veins usually two, the inner one 2–4 mm , the outer one 0.9–1 mm , and occasionally a third vein perceptible 0.2–0.3 mm from the usually plane margin, this with a dark brown shining girdle to 0.2 mm wide. Inflorescences axillary or ramiflorous, fasciculiform, the central axis not developed, with 2–4 flowers; bracts widely ovate, to 1 × 1 mm ; pedicels 2.5–5 × 0.5–0.6 mm , applanate; bracteoles ovate or elliptic, to 1 × 0.8–1.2 mm , persisting after anthesis, sometimes carenate; flower buds not seen; ovary to 1 mm , somewhat verrucose; sepals four, elliptic or widely triangular, in two slightly unequal pairs, the smaller ones 1.5–2 × 2 mm and the larger ones 2–2.5 × 2–2.6 mm , sometimes with a hyaline margin to 0.2 mm wide, patent after anthesis, glandular as the blades, the glands sometimes markedly excavate; petals, stamens and style not seen; staminal ring to 2.2 mm in diameter and 0.4 mm thick; calyx tube absent or to 0.1 mm deep; ovary with two internally glabrous locules, with 8 to 11 ovules per locule. Fruits not known. Distribution, habitat and phenology:—This species is presently known only from the type specimen, collected in lowland sandy fields (“campinas”) of the municipality of Humaitá, in the southern portion of the state of Amazonas ; flowers were colleted in November. Affinities:—This species is morphologically close to Eugenia cribrata , a species known from Colombia and Venezuela ( Govaerts et al. 2022 ) due to its marked glandular dots, and may occasionally be confused with the widespread South American Eugenia egensis ; it is compared with both species in the diagnosis. Considering its fasciculiform inflorescences it may be assigned to Eugenia section Umbellatae , according to the sectional classification of Mazine et al. (2016 , 2018 ). Conservation status:—The municipality of Humaitá has an area of 33,111 km ² from which there are recorded 9,657 collections, resulting in the low collection index of 0.3 collection/km². Considering that the species is known only from the type , collected forty years ago, the species must be scored as Data Deficient (DD) according to IUCN conservation criteria ( IUCN 2019: 72 ). Etymology:—The epithet is allusive to the collection site, the municipality of Humaitá.