Myrcia polygama (O.Berg) M.F.Santos

Santos, Matheus F., 2025, Taxonomic monograph of Myrcia sect. Eugeniopsis (Myrciinae, Myrteae, Myrtaceae), an endemic clade of Eastern South America, Phytotaxa 703 (1), pp. 1-100 : 53-54

10. Myrcia polygama (O.Berg) M.F.Santos (in Santos et al. 2019: 6) ( Figures 18 , 29–31 ).

≡ Eugeniopsis polygama O. Berg (1857 –1859: 147). Marlierea polygama (O.Berg) D. Legrand (1962a: 30) . Type:— Brazil, no date (fl.), Sellow s.n. (staminate specimen) (lectotype K! [K000330558] designated by Santos et al. 2019; isolectotypes BR! [845152], K! [K000330560], LE! [LE00004009], P! [P00217969], P! [P00217971], W! [2004-08262]). Excluded syntypes (= Myrcia vellozoi ):— Brazil, no date (fl.), Sellow s.n. (hermaphrodite specimen) (BR! [845119], F! [936892] [image], K! [000330559], LE! [LE00004010], P! [P00217968], P! [P00217970]).

Description:— Shrub to tree, 2 to 25 m high. Trunk greyish, cork realising thin strips. Trichome reddish, simple or dibrachiate, 0.04–1.0 mm. Twig when young flattened and sometimes distally sulcate, tomentose or puberulent, when mature greyish (when dry), cylindrical, cortex slightly cracked; monopodial, internode 1.2–5.8 cm, node slender; cataphylls present, early deciduous; buds pubescent. Leaf concolorous, chartaceous, blade 5.5–14.8 × 1.6–5.5 cm, narrowly elliptic to elliptic, lanceolate to ovate, apex acuminate or caudate, base cuneate to rounded or attenuate, margin plane, secondary veins 1–7 mm apart, held at an angle of 70–85° relative to the midvein, one or two marginal veins, the first 0.5–3.0 mm and the second 0.5 mm from the margin, tertiary veins usually inconspicuous in both surfaces, areoles 0.5–1.5 mm, pellucid dots conspicuous in the abaxial surface, 3–17 per mm 2; adaxial surface glabrous, secondary veins usually plane; abaxial surface subglabrate to glabrous (often puberulent), secondary veins plan to slightly raised; petiole 5–19 × 1–2 mm, canaliculate, puberulent to glabrous. Inflorescence 1.5–10.2 × 1.0– 9.5 cm, 15–185 flowers, axillar at the terminal or subterminal nodes of the SGU (central bud developing a vegetative branch), usually with a short internode with a pair of branches and an abortive central bud, inflorescence pherophyll persistent or deciduous, opposite branching, three (rarely five) branching per node, rachis pubescent to puberulent, first internode of central rachis 1–3 mm wide; bracts 0.6–2.0 × 0.6–2.0 mm, deciduous, lanceolate to ovate or rounded, concave to plane or keeled, apex acuminate to rounded, base narrowly cuneate or truncate, both surfaces puberulent; bracteoles 0.6–0.8 × 0.2–0.4 mm, deciduous, linear, lanceolate to ovate, concave, apex acuminate to acute, base truncate, both surfaces puberulent. Flower bud 1.4–5.0 × 1.0–3.0 mm, clavate, corolla hidden or barely apparent before anthesis; hypanthium 0.8–1.2 mm extending above the summit of the ovary, not tearing at anthesis or with a small vertical rip (but not tearing the staminal ring), externally tomentose or pubescent to puberulent, pellucid dots covering the whole surface (but usually covered by the indument); calyx 4–5–merous, lobes 0.4–1.2 × 0.5–1.5 mm, not fused, deciduous parallel to the hypanthium ring, depressed ovate to widely depressed ovate, concave (rarely plane), apex rounded, externally puberulent to glabrous, internally puberulent; corolla 3–4–merous, petals white, 0.8–1.9 × 0.6–1.9 mm, depressed ovate to widely depressed ovate, very widely ovate or very widely obovate, concave to plane, apex rounded, both surfaces puberulent to glabrous; bisexual and staminate flowers with staminal ring 0.2–0.4 mm wide, puberulent to glabrous, stamens 24–101, filament 1.5–4.2 mm long, anther 0.16–0.32 × 0.24–0.40 mm, gland at the apex; bisexual flower with ovary 0.6–1.0 × 0.5–0.8 mm, obconic, style 6.0–7.0 mm long, glabrous, stigma punctiform (papillose), staminate flower with vestigial pistiloid. Fruit immature green, mature vinaceous, 0.8–1.3 × 0.8–1.3 cm, globose, base rounded or obconic, glabrescent, totally covered by pellucid dots, remnants of hypanthium and calyx present; seeds 1 or 2 per fruit.

Distribution and Habitat: — Myrcia polygama is found within the Atlantic Forest domain, occurring in the states of Bahia, Espírito Santo, Rio de Janeiro and Minas Gerais ( Figure 18 ). The species usually inhabits in lowland rainforest and restinga vegetation, though there are some records from semideciduous forests and forests areas within the Cerrado domain. It typically grows in the forest understory or along forest edges, including also riparian forests, at elevations ranging from 10 to 1,007 meters.

Phenology: —Flowering occurs from September to December, with a peak in September and October. Fruiting occurs from October to March, as well as in June and July, with mature fruits recorded only in June.

Conservation Status: — Myrcia polygama has a relatively broad distribution area (Extent of Occurrence is 310,716 km 2, threshold of Least Concern), but with only 42 records and a limited Area of Occupancy (100 km 2, threshold of Endangered) (sensu IUCN 2022). Giving this conflicting data, the species is classified as Data Deficient (DD; IUCN 2022), though it warrants attention for conservation purposes.

Taxonomy: — Myrcia polygama is characterized by androdioecy, monopodial branching, typically narrowly elliptic or lanceolate leaves with elongated (acuminate or caudate) apices and generally glabrous or subglabrate surfaces, long petioles, many flowered inflorescence arising at subterminal or terminal nodes of the SGU (often with a short internode with a pair of symmetrical inflorescences), calyx 4-5-merous, and corolla 3-4-merous. The remaining syntypes cited by Santos et al. (2019) (Sellow s.n.) were excluded from M. polygama as their morphology align more closely with M. vellozoi . Inland specimens of M. polygama (Faria 666, 950, Mendes s.n. (BHCB163940), Ramalho 2788, 2647, Silva 742, Sobral 13371, 14387, Vidal 632) shows similarities to Myrcia clausseniana , distinguishable by leaf blade morphology; additionally, only M. polygama exhibits androdioecy, although no staminate specimens were not found in the inland region. Specimens from southern Bahia ( Jardim 2267, Mori 11027, 13977, 14033) resemble Myrcia vellozoi , but differ by their androdioecy, paired inflorescences on short internode, and smaller flower bud. Vernacular names recorded for M. polygama in Minas Gerais include “amarelinho” and “jambo”.

Illustrations and images in previous works: — Scaravelli et al. (2022).

Additional specimens examined: — BRAZIL. Bahia: Mun. Barro Preto, 29 July 2004 (fr.), A. M. A . Amorim 4213 ( BHCB, CEPEC, SPF); ibidem, 10 December 2005 (fl.), J. G . Jardim 4794 ( CEPEC, HUEFS, NY, RB, SPF). Mun. Caravelas , 9 November 2007 (fl.), A. C. S . Cavalcanti 25 ( NY, RB, SPF); ibidem, 9 October 2007 (fl.), H. M . Dias 292 ( RB). Mun. Una , 13 May 1981 (st.), S. A . Mori 13977 ( CEPEC, NY); ibidem, 14 May 1981 (st.), S. A . Mori 14033 ( CEPEC, NY); ibidem, 26 February 1978 (fr.), S. A . Mori 9306 ( K, RB); ibidem, 29 October 1978 (fl.), S. A . Mori 11027 ( NY, RB); ibidem, 27-28 October 1999 (fl.), J. G . Jardim 2267 ( BHCB, CEPEC, NY, RB). Espírito Santo: Mun. Aracruz, 11 October 1995 (fl.), M. A . Assis 621 ( SP, UEC); ibidem, 19 October 1993 (fl.), O. J . Pereira 5103 ( SPF, VIES); ibidem, 28 October 1992 (fl.), O. J . Pereira 4022 ( RB). Mun. Cariacica , 11 January 2007 (fr.), L . Kollmann 9475 ( MBML, SPF); ibidem, 26 October 1999 (fl.), J. M. L . Gomes 3325 ( SPF, VIES). Mun. Conceição da Barra , 18 October 2008 (fl.), A. G . Oliveira 357 ( RB); ibidem, 31 October 2014 (fl.), J. E. Q . Faria 4236 ( RB); ibidem, 26 March 1992 (fr.), O. J . Pereira 3159 ( SPF, VIES); ibidem, 9 June 1992 (fr.), O. J . Pereira 3427 ( RB); ibidem, 14 October 1999 (fl.), O. J . Pereira 3921 ( RB, SPF, VIES). Mun. Linhares , 10 November 1986 (fl.), G . Hatschbach 50772 ( CEPEC, K, MBM, NY, US) ; ibidem, 13 October 2002 (fl.), K . Matsumoto 807 ( SPF, UEC); ibidem, 14 November 1991 (fl.), O. J . Pereira 2441 ( SPF, VIES); ibidem, 16 December 1996 (fr.), O. J . Pereira 5765 ( SPF, VIES); ibidem, 3 September 2011 (fl.), A. O . Giaretta 998 ( RB, VIES); ibidem, 3 October 1972 (fl.), A. M . Lino 122 ( RB); ibidem, 3 October 1972 (fl.), A. M . Lino 125 ( NY, RB); ibidem, 15 September 2004 (fl.), D. A . Folli 4932 ( BHCB, K, SPF); ibidem, 4 September 1978 (fl.), I. A . Silva 19 ( BHCB, CVRD, SPF, UEC). Mun. Presidente Kennedy , 7 August 1990 (fl.), J. M. L . Gomes 1320 ( RB446519 ) . Minas Gerais: Mun. Caratinga, 11 October 1983 (fl.), M. C. W . Vieira 732 ( UEC). Mun. Descoberto , 25 September 2002 (fl.), L . D.Meireles 1167 ( BHCB). Mun. Itabira, 11 November 2010 (fr.), J. E. Q . Faria 950 ( BHCB). Mun. Lagoa Dourada, 3 October 2009 (fr.), J. E. Q . Faria 666 ( BHCB). Mun. Lavras , 2 October 2004 (fl.), A. F . Silva 742 ( BHCB). Mun. Ritápolis , 16 September 2010 (fl.), M . Sobral 13371 ( RB). Mun. São Brás do Suaçuí , December 2011 (fr.), M. S . Mendes s.n. ( BHCB163940 ); ibidem, 15 November 2011 (fr.), M . Sobral 14387 ( RB, SP). Mun. São Gonçalo do Rio Abaixo , 27 July 2006 (fl.), C. V . Vidal 632 ( BHCB, RB). Mun. São Roque de Minas , 15 October 1983 (fl.), R. S . Ramalho 2647 ( RB); ibidem, 15 October 1983 (fl.), R. S . Ramalho 2788 ( RB). Mun. Viçosa , 4 October 1978 (fl.), R. S . Ramalho 1269 ( RB).

Figures

FIGURE 18. Distribution of Myrcia ferruginosa (triangles) and Myrcia polygama (circles). Solid lines represent the boundaries of South American countries and Brazilian states. The grayscale reflects elevation.

FIGURE 29. Representative specimens of Myrcia sect. Eugeniopsis: Myrcia polygama (Folli 4932 [SPF]).

FIGURE 30. Representative specimens of Myrcia sect. Eugeniopsis: Myrcia polygama (Pereira 5765 [SPF]).

FIGURE 31. Representative specimens of Myrcia sect. Eugeniopsis: Myrcia polygama (Gomes 3325 [SPF]).