Myrcia fria Sobral, 2017

Sobral, Marcos, Costa, Idimá G., Souza, Marcelo C. & Zorzanelli, João Paulo F., 2017, Five new species and one new combination in Brazilian Myrtaceae, Phytotaxa 307 (4), pp. 233-244 : 240

4. Myrcia fria Sobral , sp. nov.

Type:— BRAZIL. Espírito Santo: Santa Teresa, São Lourenço, Mata Fria de Clerio Loss , 25 June 1998, L. Kollmann, E. Bausen & W. Pizziolo 138 (holotype MBML! ; isotypes HUFSJ!, RB!) .

Figure 4 .

Diagnosis:—This species is apparently related to Calyptranthes pauciflora , from which it differs by its leaves with longer petioles (4–6 mm vs. up to 2 mm in C. pauciflora ), blades with acumen about 20% of the blade length (vs. up to 10%), inflorescences axillary (vs. auxotelic) with up to five flowers along its axis (vs. up to three flowers at the apex of the axis), and glabrous flowers (versus with rufescent trichomes) with calyptra not apiculate (vs. apiculate).

Description:—Tree 8– 18 m. Plants glabrous except for very scattered hyaline dibrachiate trichomes to 0.2 mm along the abaxial side of blades. Twigs light grey when dry, semiterete and slightly longitudinally striate, the internodes 10–50 × 1–1.5 mm. Leaves with petioles 4–6 × 0.8–0.9 mm, black when dry, adaxially sulcate; blades elliptic or narrowly elliptic, 50–70 × 15–30 mm, 2.3–3 times longer than wide, discolorous when dry, dull olive-green adaxially and light green abaxially; glandular dots 10 to 15/mm², smaller than 0.1 mm in diameter, visible only adaxially, there darker than the surface and moderately excavate, not visible abaxially or backlit; base cuneate; apex acuminate in 7–13 mm; midvein finely impressed and moderately raised abaxially; lateral veins 15 to 20 at each side, very faintly visible adaxailly, finely raised abaxially, leaving the midvein at angles ca. 70°, secondary lateral veins perceptible only abaxially; marginal vein 0.5–0.6 mm, occasionally a second marginal vein to 0.2 mm of the margin. Inflorescences racemiform, with 3 to 5 flowers, the main axis 10–19 × 0.8–1 mm, the peduncle up to 10 mm, visibly applanate, occasionally solitary flowers at the apex of an axis (which in this case can also be interpreted as a pedicel) to 7 × 1 mm; bracts not seen, possibly deciduous before anthesis; frequently at the position of bracts there are three to five linear colleters to 0.3 × 0.1 mm; pedicels absent or 0.5–0.8 × 0.5–0.6 mm; bracteoles not seen, possibly deciduous before anthesis; flower buds obovate, 3–4 × 3 mm; calyx lobes fused in one calyptra to 4 mm in diameter and 1 mm long, apically rounded and not apiculate, markedly reflexed at anthesis; petals not seen in the specimens examined, possibly abortive; stamens not counted, the filaments to 5 mm, the anthers globose or oblate, 0.2–0.4 × 0.4 mm, eglandular; staminal ring to 3 mm in diameter, its entire margin reflexed at anthesis; calyx tube to 2 mm deep; style to 7 mm, the stigma punctiform; ovary with two locules and two to three ovules per locule. Fruits globose, 15–20 mm in diameter, immature; seeds not examined.

Distribution, habitat, and phenology:—Presently known only from the municipality of Santa Teresa, where it was collected in montane rainforests at about 750 m elev.; flowers were collected in February and August and fruits in November.

Conservation:—The municipality of Santa Teresa, with an area of 683 km ² ( IBGE 2016b) is one of the most intensely surveyed sites in the state of Espírito Santo, with 30,176 collections registered ( INCT 2016), resulting in a high average of 44 colections/km². Considering this large sampling, the fact that only four collections are known for Myrcia fria may be an indicative of its rareness. Although some specimens were collected inside a preserved area, the Santa Lúcia Biological Station, the municipality of Santa Teresa is a “severely fragmented area” (IUCN criterion B1a) with “a constant decline of extent” [IUCN criterion B1b(iii)], as there is information that only 18% of the original vegetation of Santa Teresa remain ( Mendes & Padovan 2000); additionally, as the extent of occurrence of the species is smaller than 5,000 km ² (IUCN criterion B1), this species fits IUCN criteria B1 ab(iii) of the Endangered (EN) category ( IUCN 2001).

Etymology:—The epithet is derived from the collection site of the type specimen—Mata Fria—used in apposition.

Affinities:—Apparently related to Calyptranthes pauciflora O. Berg (1857 –1859: 543; no type image available online), a species from coastal Brazilian forests, with which it is compared in the diagnosis. The genus Calyptranthes Swartz (1788: 79) has been until now recognized as independent from Myrcia De Candolle (1827: 406) . Nevertheless, since the publication of the phylogenetic scheme proposed by Lucas et al. (2011), it was recognized that the genus Calyptranthes was nested in a clade formed by species assigned to Myrcia (“ Myrcia group”). Since conservation of Myrcia was recently accepted by the International Committee for Botanical Nomenclature ( Wilson 2017: 189), the present new species is already assigned to the genus Myrcia .

Note:—The twigs of some specimens present scattered raised black dots to 1 mm in diameter, a very remarkable feature not included in the description, since these dots apparently represent an epiphytic lichen.

Paratypes:— BRAZIL. Espírito Santo: Santa Teresa, Estação Biológica de Santa Lúcia , 18 August 1993, L.D. Thomaz 1403 ( MBML!) ; idem, 18 August 1993, L.D. Thomaz 1440 ( MBML!) ; idem, 25 November 1998, L. Kollmann, E. Bausen & W. Pizziolo 1097 ( MBML!, UEC) .

Figures

FIGURE 4. Myrcia fria. Isotype at HUFSJ.