Myrcia chocoensis

Parra-O, Carlos, 2021, Thirteen new species, new records, and a new combination on Colombian Myrtaceae, Phytotaxa 497 (3), pp. 175-210 : 194

8. Myrcia chocoensis C. Parra-O., sp. nov.

Type :— COLOMBIA. Chocó: Quibdó, “Carretera Yuto-Lloró”, ca. 80 m, 30 June 1983 (fr.), E. Forero, R. Jaramillo, J. Espina & L. Quiñones 9639 (holotype COL!, isotype MO!). Figure 10 .

Diagnosis:—This species is most similar to Myrcia aliena McVaugh (1958: 627) , from which it is distinguished by having whitish hairs (versus yellowish or pale reddish hairs in M. aliena ), leaf blade base with the tissue decurrent down to the first ¼ of the petiole’s length (vs. not decurrent), peduncles of the inflorescences 4.5– 7 cm (vs. 1–3 cm), and calyx lobes spreading in fruit (vs. erect).

Description:—Tree; hairs when present 0.2–0.3 mm, simple, whitish; young branches compressed, yellowish brown, glabrous to slightly pubescent; old branches not seen. Leaf blades obovate to broadly obovate, sometimes elliptic, 4–7 × 2.7–4 cm, coriaceous, discolorous, the upper surface glabrous, with impressed glandular dots not perceptible, the lower surface glabrous, with slightly raised glandular dots; apex obtuse or rounded, the tip itself acuminate in 2–5 mm; base cuneate or obtuse with the leaf blade tissue decurrent down to the first ¼ of the petiole; margin entire; midvein markedly sulcate and slightly pubescent above, markedly convex and almost glabrous to slightly pubescent below; lateral veins 14–20 pairs, flat to slightly convex and glabrous above, slightly convex and glabrous below, venation joining in an inframarginal vein at 1–2 mm from margin; petioles 4–8 mm long, blackish above and below, moderately rugose, scarcely to moderately pubescent, canaliculate adaxially. Inflorescences axillary, paniculate, 7–10 cm long, flowers per panicle unknown, axes subcompressed, almost glabrous to slightly pubescent, yellowish brown to brown when dry; peduncles 45–70 × 1.5–1.8 mm; bracts and bracteoles not seen; flower buds and open flowers not seen. Fruits globose, yellowish brown to dark brown when dry, 6–7.5 mm in diameter, glabrous, sessile, occasionally pedicellate, the pedicel subcompressed, 0.5 × 0.5–0.8 mm, glabrous, calyx lobes five, persistent in fruit, in some fruits two lobes are larger than the other three, lobes very broadly ovate or depressed ovate, 0.3–0.7 × 0.5–1 mm, coriaceous, glabrous to scarcely pubescent outside, slight to moderately pubescent inside, apex obtuse, remnant staminal ring on fruit circular, 1.7–2 mm diameter, glabrous, apparently swollen and the central portion appears sunken; mature seeds not seen.

Distribution, habitat and phenology:— Myrcia chocoensis grows in tropical humid forests of the Chocó Biogeographic Region located at the Chocó Department, at ca. 80 m; it seems to be endemic to Colombia. This species has been collected with fruits in June.

Conservation:—The conservation status of Myrcia chocoensis is assessed as Data Deficient (DD) following IUCN Red List criteria ( IUCN 2019), because this species is currently known from only one location at the municipality of Quibdó.

Etymology:—The specific epithet of the new species refers to the department of Chocó, Colombia, where the type was collected.

Affinities:— Myrcia chocoensis is apparently related to Myrcia aliena , and both species can be separated using the characters provided in the diagnosis. In most of the fruits of the type specimens of M. chocoensis the remnant staminal ring is apparently swollen and the central portion appears sunken ( Figure 10 C ), and in the dissected fruits the seeds were deformed. Flowering specimens and additional fruiting specimens are in need to evaluate if the characters of the staminal ring observed here are constant for this species, or if is a particular variation in the fruits of the holotype.

Figures

FIGURE 10. Myrcia chocoensis. (A) fruiting branch, (B) leaf base, (C) upper view of fruit with remnants of the calyx lobes. A–C from the holotype. Scale bar for B and C = 2 mm.