Eugenia dentata (O.Berg) Niedenzu (1893: 82)

Sobral, Marcos, Bünger, Mariana O., Chagas, Arlindo, Lacerda, Marco Túlio Côrtes De, Lima, Igor Gonçalves & Tyski, Lourival, 2025, Notes on Eugenia dentata (Myrtaceae), Phytotaxa 700 (1), pp. 18-28 : 19-27

Eugenia dentata (O.Berg) Niedenzu (1893: 82) .

Basionym:— Stenocalyx dentatus O. Berg (1857 –1859: 338). Type:— BRAZIL. Pará: without locality, without date, Sieber [“Siber”] s.n., “Commun. Comes de Hoffmannsegg, 1826” (lectotype BR 000000523019!, designated by McVaugh 1969: 177) ( Figure 1 ). Possible isolectotype:— BRAZIL. Without data, Sieber (?) (M 0137692, image) ( Figure 2 ). Epitype (designated here):— BRAZIL. Ceará: São Benedito, São José, 7 February 2018, A.S.F. Castro 3011 (EAC!, image EAC 62166) ( Figures 3 , 4 ). ≡ Eugenia dentata (O.Berg) Mattos, 1989: 3 , nom. illeg. ( Figures 1–9 .)

Description:—Trees 3.5–15 m tall. Bark rugose, longitudinally striate, occasionally the cortex detaching in longitudinal plaques becoming smooth and light grey or light brown (figure 5). Twigs semiterete, drying light brown or sometimes reddish, glabrous or with scattered simple whitish trichomes to 1 mm long, the internodes 20–40 × 0.8–2 mm. Leaves with petioles 2–4 × 0.5–0.9 mm, drying dark green, semiterete, adaxially sulcate, glabrous or with very scattered trichomes ca. 1 mm as the twigs, occasionally with two or three linear colleters to 1 × 0.1 mm at the adaxial portion of the base; adult blades elliptic, 50–90 × 20–41 mm, 1.9–3 times longer than wide, essentially glabrous, sometimes with trichomes as the twigs scattered along the abaxial face, especially on the midvein, adaxial face drying shining green or brown, abaxial face dull light green; base cuneate; apex acuminate in 10–14 mm, sometimes drying conduplicate; glandular dots 15–25/mm², smaller than 0.1 mm in diameter, visible and slightly excavated adaxially, more scarcely visible abaxially and very evident when backlit; midvein adaxially impressed and abaxially raised and somewhat darker than the surface; lateral veins 6–9 at each side, raised on both sides, leaving the midvein at angles 45–70°; higher order venation perceptible on both faces; intramarginal veins two, the inner one formed by the confluence of the arches of the lateral ones (sometimes the basalmost lateral vein is not confuent with the others), 4–5 mm from the margin, the outer one continuous, 1–1.5 mm from the margin, the margin itself plane or slightly undulate. Inflorescences auxotelic, arising usually coeval with new leaves from defoliated branches (occasionally the flowering persists even along with adult leaves; see specimen Ducke s.n. RB 18633 and figure 6), each inflorescence originating two to six leaves at its apex which usually turn adult along with ripe fruits, the young leaves 15–20 × 5–8 mm at anthesis, moderately covered with silky simple white trichomes 1–1.5 mm and with the margins occasionally markedly undulate and folding in a complicate pattern, so seemingly toothed (hence the specific epithet); bracts linear, 3.5–10 × 1–3 mm, involute, with scattered white trichomes to 1 mm and frequently with tufts of linear colleters 0.3–1 × 0.1–0.2 mm at the base and scattered between their bases (figure 7); flowers two or four per inflorescence, the pedicels 17–25 × 0.3–0.5 mm, applanate and with scattered trichomes to 1 mm; bracteoles not seen, deciduous before anthesis (described by McVaugh [1969: 177] as “minute, scarious, linear, 0.5–1.5 mm long, situated on the pedicel 3–5 mm below the base of the hypanthium”), the apex of the pedicels with two opposite or subopposite tufts of 6–10 linear colleters 0.4–0.8 × 0.1–0.2 mm, 1–2 mm below the flower junction (probably the insertion point of the bracteoles); flower buds not seen; hypanthium densely covered with white simple appressed trichomes to 0.5 mm, with 8 scarcely to moderately visible longitudinal ridges; sepals four, oblong, 3–4 × 2–2.1 mm, reflexed at anthesis, with white or reddish simple trichomes to 1 mm scattered along them, these usually more dense at the very tips; petals four, oblong to oblanceolate, to 7 × 3–3.5 mm, glabrous or with very scattered trichomes as the sepals; stamens with filaments to 5 mm, the anthers 0.3–0.4 × 0.2 mm, apparently eglandular; staminal ring to 2 mm in diameter, with white trichomes to 0.2 mm; calyx tube absent or mostly 0.1 mm deep; style glabrous, 5–6 mm, the stigma punctiform; ovary with two internally glabrous locules and 2–3 ovules per locule. Fruits globose or slightly oblate, with 8 longitudinal ridges, these either slightly perceptible or clearly visible, to 15 mm in diameter when dry, in nature up to 20 × 20–25 mm, yellowish or orange when ripe, edible and with the pulp singularly viscose and sticky; seed one, more or less reniform, to 15 × 10 mm, the testa white and easily detachable, the embryo with cotyledons and hypocotyl completely fused and indistinguishable.

Distribution, habitat and phenology:— Eugenia dentata is presently known from the northern and northeastern Brazilian states of Amazonas, Ceará, Maranhão and Pará, where it was collected in field vegetation, upland forest and floodable forest environments; flowers were collected in September and November and ripe fruits in February, October and November. The records of Eugenia dentata known to us from the states of Amazonas and Maranhão are the photographs presented here (figures 8 and 9); the Amazonian specimen was herborized, but unfortunately the plant was destroyed along its transportation. Internet databases (e.g. specieslink.net) also list specimens from the northeastern Brazilian state of Bahia and French Guiana. The specimen from Bahia (“Bahia, Monte Santo, 39°20’ W, 10°27’ S, 20 February 1974, R.M. Harley 16431 ”, K, NY, P, U, US, images) was collected in dry forest vegetation (“caatinga”). Although initially identified as Eugenia dentata by Rogers McVaugh, it was recently described as a species of its own, Eugenia funchiana K.Coutinho & M.Ibrahim (in Coutinho et al. 2015: 218). Two sterile specimens from French Guiana identified as E. dentata (“Borne Frontière 1, 54°25’28” W, 2°12’43” N, 3 October 2006, J.F. Molino 2293 ”, and “Piton de l’Armontabo, 52°19’ W, 3°42’ N, 14 December 2006, D. Sabatier 5167 ”, both in K with images) have larger and slightly longer blades ( Molino 2293 has blades to 150 × 45 mm, ca. 3.3 times longer than wide and 7–8 lateral veins, and Sabatier 5167 blades to 130 × 40 mm, ca. 3.2 times longer than wide and 14–15 lateral veins) with very lax reticulation. They very probably do not belong to Eugenia dentata , and may well represent two other distinct species.

Affinities:— Eugenia dentata belongs to Eugenia P.Micheli ex Linnaeus (1753: 470) sect. Eugenia (for a discussion on sections see Mazine et al. 2016); it is morphologically related to the widespread South American Eugenia uniflora Linnaeus (1753: 470) , the pitanga or surinam cherry, from which it is distinguished by the cortex rugose and longitudinally striate, occasionally detaching in longitudinal plaques (versus cortex usually smooth and not striate, if detaching this occuring in irregular pieces, never longitudinally in E. uniflora ), the adult blades with venation markedly reticulate (vs. higher order venation scarcely evident) and by the larger fruits which are yellowish or orange when ripe (vs. red, purple or blackish); additionally, the pilose hypanthium in E. dentata may be an useful character, although some specimens of E. uniflora very occasionally present this feature. Specimens with young leaves are also prone to be confounded in herbaria with the widespread Eugenia patrisii Rohr ex Vahl (1798: 345 ; for description see McVaugh 1958: 719), but in E. dentata the indumentum is whitish (versus reddish in E. patrisii ), bracteoles are beset 2- 5 mm below the flowers (vs. at the base of the hypanthium), the sepals are oblong and reflexed at anthesis (vs. rounded and not reflexed), the ovary is pilose and longitudinally ridged (vs. glabrous and not ridged) and the fruits are yellow and longitudinally sulcate when ripe (vs. red and smooth when ripe). The fruits of Eugenia dentata taste reminiscent of those of acerola or barbados cherry ( Malpighia emarginata De Candolle ; 1824: 578) as a counterpoint to the typical taste of surinam cherry (A. Chagas, pers. obs.). Additionally, the pulp of the fruits from both species are markedly distinct; in Eugenia dentata it is frequently as sticky as a sort of glue, a feature absent in fruits of Eugenia uniflora . A curious feature is the scent of the leaves in nature; those of Eugenia dentata have a markedly scent of fruits of guava ( Psidium guajava Linnaeus ; 1753: 470), while leaves of E. uniflora scent like the fruits of the species itself (Chagas and Sobral, pers. obs.).

Vernacular names:—Ginja (according to collection Black 47-1688), ginja-da-mata (according to E-Plants 2024), guabiroba-de-quina, pitangaúba (these last two according to Lima 2023: 125).

Lectotypes:—There are two specimens of Stenocalyx dentatus examined by Berg and bearing his handwriting; both were in Martius’ collection at Munich in Berg’s time. Later, part of Martius’ herbarium was purchased by Meise Botanical Garden (see Martius’ Flora Brasiliensis 2024). One specimen of S. dentatus went to Meise and was studied by McVaugh for his treatment of Guayana Highland Myrtaceae (1969); the other remained at M. The specimen at BR (figure 1) was cited by McVaugh as “type”, and must be accepted as the lectotype, although he did not used this term (Article 9.10 of the Code states: “The use of a term defined in the Code as denoting a type, in a sense other than in which it is so defined is treated as an error to be corrected.” [ Turland et al. 2018: 34]). The date “1826” cited in the label after the name of Hoffmannsegg (Johann Centurius Graf von Hoffmannsegg, 1766–1849) probably refers to the date when the specimen was delivered to Munich herbarium rather than the collection date, since Sieber, who collected in Brazil under the auspices of Hoffmannsegg, returned to Europe in 1807 (see Urban 1906: 111).

The specimen at M (figure 2) is possibly a duplicate of Sieber’s collection; it bears two labels, one with the name Stenocalyx dentatus in Berg’s handwriting and the possible locality (“Brasilia?”), and a smaller one identifying it as Eugenia ; the specific epithet in the label is hardly legible and a plausible interpretation is “ divaricata ”. If this guess is correct it is interesting to note that one of the labels accompanying the lectotype at BR bears the identification Eugenia divaricata Lamarck (1789: 202 ; the combination Myrcia divaricata (Lam.) De Candolle [1828: 243] is also present in the same label), promptly contested by Berg, who wrote next to this “Maxime ab illa specie diversa”, that is, “very distinct from that species”. The Munich specimen is cited as collected by Sieber in Jstor Global Plants (2024), but there is no definitive indication for it in the label, although the erroneous identification as Eugenia divaricata on both sheets may hint that BR and M plants are duplicates.

Epitype:—Article 9.9 of the Code ( Turland et al. 2018: 34) defines an epitype as “(...) a specimen or illustration selected to serve as an intepretative type when (...) all original material associated with a validly published name is demonstrably ambiguous and cannot be critically identified for purposes of the precise application of the name to a taxon. (...)”. Since the type specimens of Eugenia dentata present flowers along with very young leaves, they are of little help in identifying collections with mature leaves and fruits. We consider that proposing an epitype with fully grown leaves and fruits fits the intention of Article 9.9. The epitype Castro 3011 (figures 3, 4) was chosen for presenting adult leaves and ripe fruits attached to the twigs—two conditions rarely found together along the specimens examined, since frequently fruits are easily detached when dry.

Potential uses:—Although not well represented in herbaria, considering its wide area of occurrence, Eugenia dentata has attracted since a long time the attention of plant breeders. Seeds of Eugenia dentata are traded in internet under the name Eugenia parkeriana De Candolle (1828: 271) (e.g. Anderson Tropicals 2024, E-Jardim 2024, Trade Winds Fruits 2024), a synonym of Eugenia uniflora according to Berg and so accepted since his work (see Berg 1855 –1856: 310 under Stenocalyx michelii O.Berg , the name used by him for Eugenia uniflora ). Eugenia parkeriana is also incorrectly listed in Plants of the World Online ( POWO 2024) as a synonym of Eugenia procera (Sw.) Poiret (1813: 129 ; basionym: Myrtus procera Swartz, 1788: 77 ), a distinct species belonging to section Umbellatae O. Berg (1855 –1856: 204). Seeds have also been processed by one of us (A. Chagas) in Vale mining corporation in the Carajás mine plant at the municipality of Parauapebas, Pará, and have been occasionally and successfully used there in reforestation and vegetation restoration, pointing to a possible future extension of this use.

Specimens examined:— BRAZIL. Pará: Belterra , 15 October 1947 (fr.) G.A. Black 47-1682 ( IAC!, IAN!, image U) ; idem, 15 October 1947 (fl.), G.A. Black 47-1688 ( IAC, IAN!, image NY, image U). Parauapebas , N4WS, estrada para N8 O, 6°05’55.0” S, 50°11’03.2” W, 10 September 2013 (fl.), L. Tyski 429 ( HCJS!) ; idem, Mina N5 Sul-Mina de Ferro Parauapebas , - 6°6’2.30” S, - 50°8’5.30” W, 4 October 2021 (fr.), A.S. Chagas & D.L.H. Oliveira 191 ( HCJS!) ; idem, Núcleo Urbano de Carajás , 30 November 2023 (fr.), T. L. Fonseca-da-Silva & G. Amorim 406 ( HCJS!) ; idem, Núcleo Urbano, without date (fr.), L. Tyski 1759 ( HCJS!). [Santarém], Igarapé Açu, afluente do rio Arapiuns , 25 November 1952, J.M. Pires & N. T. Silva 4396 ( IAN, image). Without municipality, rio Tapajós , 4 October 1922, A. Ducke s.n. ( RB 18633 !) .

Figures

FIGURE 1. Eugenia dentata: Lectotype at BR (photo by BR staff).

FIGURE 2. Eugenia dentata: Possible isolectotype at M (photo by M staff).

FIGURE 3. Eugenia dentata: Epitype with adult leaves and ripe fruits (Castro 3011; photo by EAC staff).

FIGURE 4. Eugenia dentata: Fruiting twig (Castro 3011; photo by Antônio Sérgio Farias-Castro).

FIGURE 5. Eugenia dentata: Bark; Serra do Ibiapaba, state of Ceará (photo by Antônio Sérgio Farias-Castro).

FIGURE 6. Eugenia dentata: Adult leaves and flowers; Praia do Pajuçara, Santarém, state of Pará (photo by Luiz Otávio Adão Teixeira).

FIGURE 7. Eugenia dentata: Detail of colleters and bracts (same individual as collection Tyski 1759. Photo by L. Tyski; scale: 5 mm).

FIGURE 8. Eugenia dentata: Detail of fruit (photo by M. Sobral in 10 November 2008 at Novo Aripuanã, Amazonas, Brazil, about 8°29’33” S, 60°57’53” W).

FIGURE 9. Eugenia dentata: Habit of the species; municipality of Colinas, state of Maranhão (photo by Sérgio Rosa, without date).