Myrcia peruviana Lima Santos & E. Lucas

Santos, Leidiana Lima Dos, Vasconcelos, Thais Nogales Da Costa, Sales, Margareth Ferreira De & Lucas, Eve, 2021, Three new species of Myrcia sect. Myrcia (Myrtaceae) from South America, Phytotaxa 520 (3), pp. 249-256 : 253

2. Myrcia peruviana Lima Santos & E. Lucas , sp. nov.

Type :— PERU. Bongara: 4 km N of Pomacochas on road to Rioja, trail down gorge to W of road, 77°55’W, 05°40’S, 2150–2200 m, 2 June 1986 (fl, fr), S. Knapp et al. 7500 (holotype: K 000331608 ! , isotype MO 2028941 -Image! ). Figure 3 .

This species is related to Myrcia riverae A. Estrada, D. Santamaria & Aguilar (2014: 452) by having dense brownish velutinous trichomes covering the plant and prominent venation on the abaxial surfaces, but differs in having leaf blades 5.2–15 × 2.8–6.5 cm (vs. 15.5–27.2 × 7–11.6 cm in M. riverae ), flower buds 2–3 mm long (vs. 4.5–5 mm long) and fruits ellipsoid (vs. globose).

Shrub to 1.5 m high. Twigs terete, densely covered with velutinous brownish simple trichomes 0.7–1 mm long. Internodes 3.3–7.5 cm. Petioles 4–9 × 2–3 mm, adaxially sulcate, tomentose; blades 5.2–15 × 2.8–6.5 cm, 1.8–2.3 times longer than wide, ellipsoid or oblanceolate, markedly discolorous, coriaceous, abaxially reticulate, covered with trichomes as are the twigs, mature adaxial surface glabrous, gland dots less than 0.1 mm in diameter, less than 10/mm 2, barely visible on both sides, bases acute, apices rounded or obtuse, margin plane when dry; midvein sulcate adaxially, raised abaxially; lateral nerves 8–7 pairs, barely visible adaxially and faintly salient abaxially leaving the midvein at angles ca. 70°; marginal vein 1–4 mm from the margin. Panicle triangular, 5–9 cm long, axillary or terminal, flowers 25–50. Flowers sessile; bracts not seen; bracteoles linear, 2–2.5 × 1 mm, concave, both surfaces pubescent; flower buds obovate, 2–3 × 2 mm, densely covered with yellowish trichomes 0.2–0.3 mm long, these more dense above the ovary; hypanthium extended 1 mm above the summit of the ovary, externally and internally pubescent; calyx 5- merous, slightly unequal, widely triangular to hemispheric, lobes 0.5–1.5 × 1–2 mm, pubescent with trichomes to 0.1 mm long adaxially and 0.3 mm long abaxially; petals 5, orbicular, 2 mm in diameter, adaxially glabrous, abaxially with trichomes to 0.1 mm long; stamens ca. 40, filaments 2 mm long, anthers ellipsoid, 1 mm long; staminal ring 2 mm in diameter, pubescent; styles 3–4 mm long, proximally with scattered trichomes to 0.1 mm long, stigma capitate; ovary 2–locular with two ovules per locule. Fruits 1.2–1.8 × 0.7–1.1 cm, ellipsoid, pubescent, pellucid gland dots covering whole surface, green when immature.

Distribution, habitat and phenology: — Myrcia peruviana occurs in the province of Bongara, Peru, in cloud forests ( Figure 2 ). It was collected presenting flowers and fruits in June.

Conservation: — Myrcia peruviana is known only from the type collection from a poorly known botanical region. Data available is insufficient to provide a conservation status for this species and it is here recorded as Data Deficient (DD), according to IUCN (2001) criteria.

Affinities: — Myrcia peruviana resembles Myrcia riverae , a species from Costa Rica (for description see Santamaria Aguilar et al. 2014), in the dense brownish velutinous trichomes that cover the plant and having prominent venation on abaxial leaf surfaces, but differs by the characters cited in the diagnosis. Myrcia peruviana may be another atypical species of Myrcia sect. Myrcia with superficial similarity to Myrcia sect. Aulomyrcia because the hypanthium of Myrcia peruviana is extended above the ovary. However, the staminal ring of M. peruviana comprises ca. 50% of the total disc width, its disc is velutinous, its fruits are ellipsoid and its calyx lobes are regular, consistent with features of Myrcia sect. Myrcia .

Etymology: —The specific epithet refers to the country where the species was collected.

Figures

FIGURE 2. Distribution map of Myrcia microcalyx, M. peruviana and M. rionegrensis.

FIGURE 3. Holotype of Myrcia peruviana (K000331608).