Myrcia suberosa M.F.Santos & T. Fernandes (2020: 96)

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 : 62

12. Myrcia suberosa M.F.Santos & T. Fernandes (2020: 96) . Type:— Brazil. Bahia: Itacaré, Ramal da barragem, 10 October 1968 (fl.), Almeida 173 (holotype CEPEC!; isotypes ICN!, K!, MICH!, SP!) ( Figures 28 , 35 ).

Description:— Tree, 12 to 25 m high. Trunk with rough and fissured cork. Trichome reddish, simple or dibrachiate, 0.4–0.6 mm. Twig when young flattened and distally sulcate, tomentose, when mature greyish (when dry), cylindrical, thick cork; branching monopodial, internode 2.3–2.5 cm, node slender; cataphylls not seen; buds tomentose. Leaf discolorous, adaxially green and abaxially ferrugineous (due to trichomes), chartaceous, blade 17.2–33.6 × 5.5–14.0 cm, elliptic or obovate, apex acuminate to acute, base rounded, truncate or emarginate, sometimes attenuate, margin plane, secondary veins 5–13 mm apart, held at an angle of 45–70° relative to the midvein, marginal vein 2.0–3.0 mm from the margin, tertiary veins conspicuous to inconspicuous in both surfaces, areoles 0.4–0.8 mm, pellucid dots conspicuous in the abaxial surface, ca. 4 per mm 2; adaxial surface puberulent, secondary veins raised; abaxial surface tomentose or puberulent, secondary veins raised; petiole 5–11 × 5 mm, semicylindrical to canaliculate, tomentose. Inflorescence ochraceous to ferrugineous in the rachis (due to trichomes), 8.5–14.5 × 7.0–12.0 cm, 40–107 flowers, axillar at the subterminal node of the SGU (central bud developing a vegetative branch), one pair per SGU, one inflorescence per axillary bud, inflorescence pherophyll deciduous, opposite branching, three branching per node, rachis tomentose, first internode of central rachis 4–5 mm wide; bracts 3.0–4.0 × 1.5–2.0 mm, deciduous, ovate, concave (sometimes nearly plane), apex rounded, base truncate, both surfaces puberulent; bracteoles 2.5 × 1.0 mm, deciduous, ovate, nearly plane, apex acute, base truncate, both surfaces puberulent. Flower bud 4.5 × 3.0– 3.5 mm, clavate, corolla hidden or barely apparent before anthesis; hypanthium 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 with pellucid dots covered by the indument; calyx 4–merous, lobes 1.2–1.6 × 1.6–3.0 mm, not fused, deciduous parallel to the hypanthium ring, depressed ovate to widely depressed ovate, concave, apex rounded, externally tomentose or puberulent, internally puberulent; corolla 4–merous, petals purple, 1.4–3.2 × 2.0–3.0 mm, widely depressed ovate, very widely ovate or very widely obovate, plane, apex rounded, externally puberulent, internally puberulent to glabrous; staminal ring 0.4 mm wide, puberulent, stamens ca. 90, filament 2.0– 5.6 mm long, anther 0.24–0.32 × 0.24–0.40 mm, gland at the apex; ovary ca. 1.0 × 1.2 mm, obconic, style 5.2–7.2 mm long, glabrous, stigma punctiform. Fruit immature green to ferrugineous green (due to trichomes), globose, base rounded, puberulent to glabrescent; seeds not seen.

Distribution and Habitat: — Myrcia suberosa occurs within the Atlantic Forest domain, with a currently disjunct distribution spanning southern Rio de Janeiro state to Southern Bahia state ( Figure 28 ). It inhabits rainforest with sand to clay soils near river courses, at elevations between of 50 to 500 meters ( Santos & Fernandes 2020).

Phenology: —This species has been observed flowering in October, with immature fruits recorded in March and June.

Conservation Status: —The species has an Area of Occupancy of only 12 km ², and following the rationality of Santos & Fernandes (2020), we preliminarily classify Myrcia suberosa as Critically Endangered (CR) according to the criteria B1a, biii ( IUCN 2022).

Taxonomy: — Myrcia suberosa is distinguished primarily by its thick cork bark and elongated leaf blades, which have a puberulent or tomentose abaxial surface. Additional diagnostic traits include elliptic or obovate leaf blades with rounded to emarginate bases, inflorescence emerging at subterminal node of the SGU, and large and tomentose flower bud. Myrcia teuscheriana shares the long leaf blade with M. suberosa , but the latter can be distinguished by its hermaphrodite sexual system (vs. androdioecious in M. teuscheriana ), thick cork on young branches (vs. thin cork), tomentose to puberulent indument on the leaves, inflorescence rachis and external surface of flower bud (vs. puberulent to glabrous), and flower bud with 4.5 × 3.0– 3.5 mm (vs. 1.6–2.0 × 0.8–1.0 mm) ( Santos & Fernandes 2020).

Illustrations and images in previous works: — Santos & Fernandes (2020).

Additional specimens examined:— BRAZIL. Bahia: Mun. Uruçuca , 24 October 2014 (st.), N . E . Oliveira 422 ( RBR) . Rio de Janeiro: Mun. Paraty , 25 October 2006 (st.), M . C . Souza 437 ( RB); ibidem, 26 March 1992 (fr.), C . Farney 3134 ( RB, SPF, UEC); ibidem, 27 June 1995 (fr.), R . Marquete 2176 ( RB, SPF); ibidem, 29 June 1993 (fr.), R . Marquete 1094 ( RB) .

Figures

FIGURE 28. Distribution of Myrcia oblongata (triangles) and Myrcia suberosa (circles). Solid lines represent the boundaries of South American countries and Brazilian states. The grayscale reflects elevation.

FIGURE 35. Representative specimens of Myrcia sect. Eugeniopsis: Myrcia suberosa (Almeida 173 [SP]).