Eugenia longohypanthiata Giaretta (2018: 284)

Giaretta, Augusto, Lucas, Eve & Sano, Paulo Takeo, 2021, Taxonomic monograph of Eugenia sect. Schizocalomyrtus (Myrtaceae: Myrteae), a group within Eugenia with unusual flowers, Phytotaxa 524 (3), pp. 135-177 : 156-159

5. Eugenia longohypanthiata Giaretta (2018: 284) .

≡ Calycorectes pohlianus Bentham ex Niedenzu (1893: 82) , not C. pohlianus Kiaerskou (1893: 117) , not Schizocalyx pohlianus O. Berg (1856a: 320) , nom. illeg. Eugenia cambucae Mattos (2005: 11), nom. illeg. Schizocalomyrtus pohliana (O.Berg) Kausel (1967: 367) , nom. illeg. Type:— BRAZIL. Rio de Janeiro: Habitat in Brasiliae , prov . Rio de Janeiro, s.d., Pohl 5844 (lectotype designated by Giaretta et al. (2018): W! [0071556]; isolectotypes: G [not found], GH [00068863-photo!], OXF! [00067686], W! [0071557]). ( Figures 1G–H , 13 ).

= Schizocalyx pohlianus var. panicularis O. Berg (1857: 358) , nom. illeg. Type :— BRAZIL. Rio de Janeiro, fl. s.d., [Pohl s.n.] (lectotype designated here: M [0171258-photo!]).

= Schizocalyx pohlianus var. triflorus O. Berg (1857: 358) , nom. illeg. Eugenia cambucae var. triflora (O.Berg) Mattos (2009: 2) Type:— BRAZIL. Rio de Janeiro, fl., s.d., [Pohl s.n.] (lectotype designated here: BR [000000523121-photo!]).

Trees 3 to 12 m tall. Young leaves with brownish to reddish trichomes 0.1–0.5 mm long, appressed, moderately sparse abaxially and on the midvein, glabrous adaxially, glabrescent. Leaves with petioles 7–20 × 1.5–2.5 mm; blades 8–33 × 3.5–7.5 cm, narrow-elliptic or elliptic; base acute or cuneate, decurrent along the petiole; apex acuminate, 1–3 cm long, narrowly acute or less often obtuse; midvein canaliculate adaxially; secondary veins 14–25 per side; marginal veins two, the innermost 3–8 mm from the margin, the outermost 0.5–3 mm from the margin. Inflorescence terminal, less often axillar, auxotelic, sometimes with a terminal flower; bracts 0.7–1 × 1.2–1.5 mm, wide-ovate; rachis 5–45 mm long, terete or also flattened at third portion, puberulent; 1–5 pairs of flowers, sessile or with pedicels 10–30 × 1.5 mm; up to one rachis per axil; bracteoles 1.5–4 × 1.5–3 mm, ovate, pubescent, deciduous before anthesis. Flower buds 12–16.5 × 9–11 mm, obovate or pyriform, calyx lobes partially fused but free at the tip leaving an aperture of 1–5 mm diameter, tearing irregularly at anthesis in 3–5 lobes, 6–13 × 5–9 mm, pubescent to puberulent outside; petals 6–8.5 × 6–8.5 mm, orbiculate or obovate; stamens curved in the bud, filaments up to 10 mm long, anthers 0.7–1.5 mm long; staminal whorls extending up to two thirds of the bud length, 16–18 mm diameter, deeply tearing at anthesis; style 10–11 mm long; ovary 2–locules, 5–10 ovules per locule. Fruits 25–32 × 15–30 mm, globose and longitudinally striate, densely covered by reddish or brownish puberulent indumentum, crowned by the remnant of the calyx and hypanthium with scars left by stamens insertion; seeds 1–2.

Etymology:— The specific epithet alludes to the extending flower hypanthium that contrasts to the standard flat hypanthium found in Eugenia , an extreme exception in the genus (see Giaretta et al. 2019b).

Distribution and habitat:— Eugenia longohypanthiata occurs in Southeastern Brazil (Espírito Santo and Rio de Janeiro), known from rock outcrop forest near to the coast and lowland forest further in the countryside, at elevation between 0 to 650 m ( Figure 14 ). Usually shrubs or small trees occurring in populations in the Ombrophilous Dense Forest in the Atlantic forest.

Phenology:— Flowers of Eugenia longohypanthiata have been collected from March to July and fruiting from May to August ( Figure 6 ).

Conservation status:— Eugenia longohypanthiata occurs in one protected area (APA do Mestre Álvaro) and in non-protected areas. Although Eugenia longohypanthiata is known from three localities with restrict EOO (2,524.4 km ²), tentative to collect this species in previous known distribution around Rio de Janeiro city was unsuccessful and is here considered locally extinct suggesting loss of habitat quality and consequent population reduction. On the other hand, APA Mestre Álvaro in Espírito Santo better ensures protection of natural populations. The three populations are isolated from each other by ca. 200 km of fragmented landscape. Eugenia longohypanthiata produces a small number of large fruits with poor dispersal ability that may contribute to the isolation of populations. Thus, it is suggested that this species should be rated as Endangered [EN B1ab(i, iii, iv)].

Comments:— Eugenia longohypanthiata has fused calyces and stamens curved rather than straight in the bud, an extreme exception in the genus. This combination of characters was likely the main reason for such taxonomic instability surrounding this species. The replaced name Calycorectes pohlianus was treated by Kiaerskou (1893) and Niedenzu (1893), as combinations based on Schizocalyx O.Berg a later illegitimate homonym. Calycorectes pohlianus Kiaersk. and C. pohlianus Nied. are treated here as indirect replacement names for the illegitimate Schizocalyx pohlianus O.Berg according to the Art. 41.3 of the Code, therefore, both are treated as nomina nova. Because of priority, Calycorectes pohlianus Benthan ex Niedenzu was chosen as the name to be transferred to Eugenia . The pre-existence of Eugenia pohliana De Candolle (1828: 264) requires a replacement name. Eugenia cambucae Mattos , a possible replacement name for Schizocalyx pohlianus O.Berg is not in accordance with Art. 38.1 of the Code due to the type reference not concerning the original place of the valid publication. Thus, Eugenia longohypanthiata was proposed ( Giaretta et al. 2018), easily recognized by staminal whorls extending up to two-thirds of the bud length which tears deeply at anthesis (see longohypanthium pattern in Giaretta et al. 2019b), and flowers and fruit densely covered by reddish or brownish pubescence. The fruit is crowned by the remnants of the calyx and hypanthium where scars left by stamen insertion are evident.

Specimens Examined:— BRAZIL. Espírito Santo: Serra , 17 March 2010, fl., D. A . Folli 6594 ( CVRD!, RB!, SPF!, UB!) . Rio de Janeiro: Itaperuna , 22 March 2015, fl., I . G . Costa 611 ( RB!), 26 June 2015, fr., A . Giaretta 1501 ( K!, SPF!), 26 June 2015, fr., A . Giaretta 1502 ( K!, SPF!), 9 June 2015, fr., I . G . Costa 651 ( RB!); Rio de Janeiro, 13 April 1977, fl., I . A . Rodrigues 88 ( K!, RB!), 17 August 1977, fr., L . Mautone 243 ( RB!), 1876, fl., Glaziou 8898 ( LE!), 29 June 1878, fl., Glaziou 9435 ( K!, P!, R!) .

Figures

FIGURE 1. Diversity of Eugenia sect. Schizocalomyrtus. A–B. Eugenia acutata. A. Auxotelic inflorescence undergoing a second phase of vegetative growth. B. Flowers at anthesis. C–D. Eugenia tenuipedunculata. C. Flowers. D. Immature fruits. E. Eugenia neoriedeliana. Flower opening via transversal tearing at the calyx base resulting in a calyptra-like structure. F. Eugenia guanabarina. Flowers opening via transversal tearing at the calyx base resulting in a calyptra-like structure (S) placed in opposition to a petal (P). G–H. Eugenia longohypanthiata. G. Flower bud tearing irregularly at anthesis. H. Immature fruits crowned by the remnant of the calyx lobes (S) and the hypanthium (H). (A–B: A. Giaretta 1460; C: J.E.Q. Faria 1000; D: A. Giaretta 1493; E: A. Giaretta 1489; F: A. Giaretta 1035; G: A. Giaretta 1500; H: A. Giaretta 1502). Photos by A. Giaretta, except C by J.E.Q. Faria.

FIGURE 6. Frequency distribution (n) of flowering (black-line triangle) and fruiting (grey-filled triangle) stages based on herbarium material of Eugenia sect. Schizocalomyrtus.

FIGURE 13. Eugenia longohypanthiata. A. Leaf branchlet with flower buds. B. Flower bud (left) and abaxial view of an open flower indicating the irregular lobes (right). C. Upper view of an opened flower showing a sepal lobe (S) and the hypanthium (H) with scars left at the point of stamen insertion. D. Inflorescence. E. Fruits showing remnants of the calyx and hypanthium. (A: I.G. Costa 611; B: D.A. Folli 6594; C: J. Miers s.n. (BM000043151); D: I.A. Rodrigues 88; E: A. L. Mautone 243).

FIGURE 14. Distribution of Eugenia longohypanthiata.