Eugenia altoalegre Sobral & M.A.D.Souza, 2017

Sobral, Marcos & Souza, Maria Anália Duarte De, 2017, Four new Myrtaceae from Amazonian Brazil, Phytotaxa 307 (1), pp. 55-64 : 55-57

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

Type:— BRAZIL. Roraima: Alto Alegre, Ilha de Maracá , Estação SEMA, 3°22’ N, 61°20’ W, 6 June 1986, M. J. G. Hopkins, K. F. Rodrigues, E. S. Silva, R. Pereira de Lima , J. Guedes de Oliveira & B. Lowy 514 (holotype INPA!; isotypes HUFSJ!, MIRR!). Figure 1 .

Diagnosis: —This species is apparently related to Eugenia tachirensis Steyermark (1957: 1014) , but distinct by its relatively shorter petioles (ratio blade length/petiole length> 10:1 versus <10: 1 in E. tachirensis ), larger blades (to 60 × 32 mm vs. to 50 × 22 mm), these elliptic (vs. elliptic-oblong) with acuminate apices (vs. acute or obtuse), lateral veins raised abaxially (vs. moderately impressed), marginal vein more distant from the margin (to 2 mm vs. up to 0.7 mm), glandular dots less numerous (up to 10/mm² vs. more than 10/mm²), these more visible adaxially (vs. more evident abaxially) and inflorescences with two or more flowers per axile (vs. one flower). It may also resemble Eugenia cydoniifolia O. Berg (1857 –1859: 229) and E. essequiboensis Sandwith (1932: 211) ; from E. cydoniifolia it can be distinguished by its blades with acute to acuminate apex (vs. obtuse in E. cydoniifolia ) with more lateral veins (to 12 vs. up to 5) and shorter petioles (ratio blade length/petiole length> 10:1 vs. <6:1) and flowers with internal wall of ovaries glabrous (vs. pilose); from E. essequiboensis it is distinguished by its wider blades (about 2 times longer than wide vs. up to 3 times longer than wide in E. essequiboensis ), relatively shorter petioles (ratio blade length/petiole length> 10:1 vs. <10:1), blades with smooth surface when dry and secondary venation clearly visible (vs. surface irregulary rugose when dry and secondary venation scarcely visible), inflorescences axillary, with up to 4 flowers, not auxotelic (vs. auxotelic, the flowers solitary), shorter pedicels (0–3 mm vs. up to 6 mm), triangular persisting bracteoles (vs. linear and deciduous before anthesis), calyx lobes in two markedly unequal pairs (vs. more or less equal between them) and stamens with anthers elliptic, to 0.7 × 0.2 mm (vs. globose, to about 0.2 mm in diameter).

Description: —Tree up to 15 m, 20 cm in diameter at body height, without buttresses and bark flaking in strips (data from type label). Twigs applanate, densely covered with simple brown erect trichomes 0.4–0.5 mm, these occasionally turning whitish and falling with age, the internodes 10–30 × 1.8–2 mm. Leaves with petioles pilose as the twigs, somewhat adaxially sulcate, 4–5 × 1 mm; blades elliptic, 45–60 × 25–32 mm, 1.7–2.2 times longer than wide, markedly discolorous when dry, dark brown and occasionally somewhat shining adaxially and dull light brown abaxially, adaxial side with very scattered whitish trichomes 0.1–0.2 mm, these easily falling, abaxial face with more persisting brown or whitish trichomes to 0.4 mm, denser along the midvein; base cuneate; apex acute or abruptly acuminate to 5 mm; glandular dots 6–10/mm², about 0.1 mm in diameter, visible, sometimes slightly darker than the surface and raised adaxially, scarcely visible abaxially, easily visible when backlit; midvein finely sulcate adaxially and raised abaxially; lateral veins 10–12 at each side, raised on both sides, more so abaxially, the secondary lateral veins with smaller gauge and visible mostly abaxially; marginal vein formed by the arches of the lateral veins, 0.8–2 mm from the markedly revolute margin, this with a brown girdle 0.1–0.2 mm wide. Inflorescences axillary (rarely ramiflorous), consisting of two to four flowers crowded at the axiles of leaves with no visible axis; bracts elliptic to rounded, to 2 × 2 mm, pilose as the twigs or less so; pedicels absent or up to 3 × 0.6 mm, pilose as the twigs; bracteoles widely triangular, 1.7–2 × 2–2.2 mm, glabrous adaxially and more or less pilose abaxially, apparently persisting at anthesis; flower buds obovate, 7.5–8 × 6–6.5 mm, the ovary densely covered with rufescent trichomes to 0.6 mm; calyx lobes four, usually with trichomes as the ovary at their basal portion abaxially, usually glabrous adaxially, in two unequal pairs, the outer ones widely elliptic, to 2 × 4 mm, the inner ones hemispheric, to 3 × 5 mm; petals four, rounded, 5–6 mm in diameter, with rufescent trichomes to 0.1 mm abaxially, glabrous adaxially; stamens not counted, filaments (in bud) 4–5 mm, anthers elliptic, to 0.7 × 0.2–0.3 mm, with one apical gland; staminal ring about 2.5 mm in diameter, with trichomes as the calyx; calyx tube absent; style 7–8 mm, stigma punctate and papillose; ovary with two locules with glabrous internal wall, each locule with about 30 ovules. Fruits not seen.

Distribution, habitat and phenology: —This species is presently known only from the municipality of Alto Alegre, in the northern portion of the state of Roraima, where it grows in primary forest with sandy soils (data from type label). Flowers were collected in June.

Conservation: —Considering that this species is known from only one collection, it must be scored as DD (Data Deficient) according to IUCN conservation criteria ( IUCN 2001).

Affinities: —This species is apparently related to the Venezuelan Eugenia tachirensis (type images: F barcode V0065338F, U barcode 0005062), the Bolivian E. cydoniifolia (for description see Villarroel et al. 2014; type image: G barcode 00223433) and the Guyanan E. essequiboensis (type image: K barcode 00261062); it is compared to both in the diagnosis. Considering the structure of the inflorescences, this species can be assigned to section Umbellatae O. Berg (1855 –1856: 204), according to the phylogenetic scheme proposed by Mazine et al. (2016).

Etymology: —The epithet is an apposition of the collection site, the municipality of Alto Alegre.

Figures

FIGURE 1. Eugenia altoalegre. Holotype (scale: 50 mm).