Myrcia subterminalis M.F.Santos, 2015

Santos, Matheus F., Lucas, Eve & Sano, Paulo T., 2015, Five new South American species of Myrcia s. l. (Myrtaceae), Phytotaxa 234 (2), pp. 159-171 : 169-170

5. Myrcia subterminalis M.F.Santos , sp. nov. ( Figs. 2 , 4F–I )

Myrcia subterminalis is related to Myrcia bicolor Kiaersk. , but differs in the predominantly monopodial vegetative branching (vs. sympodial), the terminal and subterminal inflorescences (vs. only terminal) and turbinate floral bud (vs. clavate).

Type:— BRAZIL. Espírito Santo: Mun. Santa Teresa, Reserva Biológica Augusto Ruschi, Próximo ao marco 112, seguindo o córrego, 27 August 2003 (fl.), J. Rossini 482 (holotype MBML!, isotypes SP!, SPF!).

Tree 3– 15 m. Immature parts sometimes with epidermal peeling; trichome light brown (rarely ferruginous), 0.1– 0.2 mm long, dibrachiate. Twig when immature reddish, flattened, sometimes with longitudinal grooves, not keeled, with scattered trichomes to glabrous; mature twig greyish, cylindrical, cortex slightly cracked, glabrous; branching monopodial (rarely sympodial), 2–3 branches per node (rarely more than three), epidermal protrusion absent at the internodes (present only in sympodial branching), internode 2.5–6.8 cm long; cataphyll foliaceous, 7 × 2 mm, usually only at the basal internodes, early deciduous, adnate, lanceolate, externally puberulent; branch with 1–3 apical buds, pubescent or puberulent. Leaf discolorous, chartaceous, blade 5.0–14.5 × 1.4–5.9 cm, elliptic, widely elliptic, ovate or obovate, apex caudate, base atenuate, cuneate or obtuse, margin plane, secondary veins 3–6 mm apart, held at an angle of 65–85 o relative to the midvein, marginal vein 1.0– 1.5 mm from the margin (rarely two), tertiary veins conspicuous (rarely inconspicuous); adaxial surface glabrous, midvein sulcate in the first half and flat in the second half, secondary veins flat (rarely prominent), pellucid dots inconspicuous, from 5 to 15 per mm 2; immature abaxial surface with scattered trichomes to glabrous, glabrous at maturity, midvein and secondary veins prominent, pellucid dots slightly conspicuous to inconspicuous, from 5 to 15 per mm 2; petiole 3–10 × 1–2 mm, canaliculate to semicylindrical, immature with scattered trichomes, mature glabrous. Panicle 3.5–7.0 × 2.5–3.5 cm, pyramidal, terminal axillary or subterminal, 14–70 flowers, rachis puberulent or with scattered trichomes to glabrous, branching 1–5 times at the base, first internode of central rachis 1.0– 1.5 mm wide, cylindrical to flattened, distal internodes flattened, opposite branching (rarely subopposite), 2–5 branches per node, epidermal protrusion present at the internodes, usually absent in apical branches. Bract 0.8 × 0.2 mm, deciduous, lanceolate or ovate, concave, apex acuminate, base truncate, adaxial surface glabrous, abaxial surface puberulent. Pedicel 0–2 mm long, cylindrical, puberulent. Bracteole 0.4–0.6 × 0.2 mm, deciduous, lanceolate or ovate, concave, apex acuminate, base truncate, adaxial surface glabrous, abaxial surface puberulent to glabrous. Floral bud 2–3 × 1–2 mm, turbinate. Hypanthium extending 0.6–1.0 mm above the summit of the ovary, not tearing at the anthesis, externally with scattered trichomes to glabrous, pellucid dots slightly conspicuous, covering the whole surface, internally glabrous; calyx 4–5-merous, lobes 0.4–1.0 × 0.6–1.8 mm, distinct from the hypanthium, external lobes smaller than the internal lobes, deciduous, depressed ovate, widely depressed ovate or ovate, concave, apex rounded, base truncate, externally with scattered trichomes to glabrous, internally puberulent to glabrous; corolla 4–7-merous, petal white, 0.8–2.0 × 1.0– 1.8 mm, depressed ovate, widely depressed ovate, widely ovate or very widely ovate, concave, apex rounded, base truncate, externally puberulent or with scattered trichomes to glabrous, internally glabrous; staminal ring 0.2–0.4 mm wide, glabrous, stamens 38–60, filament 1.6–5.0 mm long, glabrous, anther 0.24– 0.40 × 0.24–0.48 mm, square, oblong or transversely oblong; ovary 0.6–1.0 × 0.8 mm, 2-locular, each locule with two ovules, style 3.6–5.2 mm long, glabrous, stigma punctiform, papillose. Fruit green when immature, reddish at maturity, 7 × 6 mm, depressed globose or globose, glabrous, pellucid dots covering the whole surface, remnants of calyx lobes present or not; seeds 1–2.

Distribution and Habitat:— Myrcia subterminalis occurs in the Atlantic Forest domain, in submontane to montane rainforest (Alagoas, Bahia and Espírito Santo states) and in semideciduous forest (municipality of Bandeiras— Minas Gerais state).

Phenology:— Myrcia subterminalis flowers from July to September and in November. Fruits were found from September to January.

Etymology:—The specific epithet refers to the presence of subterminal inflorescences in this species.

Conservation status:—The species presents an Area of Occupancy smaller than 2,000 km 2 and is only recorded from few (six) localities. Moreover, it is endemic to the Atlantic Forest, a phytogeographic domain reduced to only 7.5% of its original extent ( Myers et al. 2000). Myrcia subterminalis is here considered as Vulnerable (VU, criteria B2a, biii; IUCN 2001).

Discussion:— Myrcia subterminalis resembles Myrcia bicolor but differs in its predominantly monopodial vegetative branching, terminal and subterminal inflorescences and turbinate floral buds. Myrcia subterminalis is also characterized by a strongly canaliculate petiole, leaf blades with decurrent bases and the lightly reticulate venation. Sympodial (dichotomic) branching is rarely present, but in this case one of the branches develops faster than the other and the branching becomes monopodial.

Paratypes:— BRAZIL. Alagoas: Mun. União dos Palmares, Serra das Bananeiras, 500–560 m, 9 o 12’7.75’’S, 35 o 52’4.8’’W, 3 November 2002 (fr.), W.W. Thomas 13253 ( CEPEC!). Bahia: Mun.Almadina, Serra do Corcovado , 831 m, 14 o 42’21’’S, 39 o 36’14’’W, 3 September 2011 (fl.), M.M. Coelho 360 ( CEPEC!). Mun.Arataca, 1000 m, 15 o 10’2.5’’S, 39 o 20’3’’W, 12 October 2005 (fr.), A.M.A. Amorim 5313 ( CEPEC!) ; Parque Nacional da Serra das Lontras , 26 November 2011 (fl.), M.F. Santos 757 ( SPF!) ; RPPN “ Caminho das Pedras ”, 1000 m, 15 o 10’2.5’’S, 39 o 20’3’’W, 24 September 2006 (fr.), A.M.A. Amorim 6387 ( CEPEC!) ; RPPN “Caminho das Pedras”, 936 m, 15 o 10’2.7’’S, 39 o 20’2.2’’W, 26 November 2006 (fr.), A.M.A. Amorim 6613 ( CEPEC!). Espírito Santo: Mun. Cariacica, Reserva Biológica de Duas Bocas , 600 m, 20 o 17’29’’S, 40 o 31’10’’W, 20 July 2008 (fl.), A.M.A. Amorim 7577 ( RB!). Mun. Santa Teresa, 8 August 2000 (fl.), V. Demuner 1357 ( BHCB!) ; Estação Biológica de Santa Lúcia , 22 September 1999 (fl.), V. Demuner 25 ( MBML!) ; Estação Biológica de Santa Lúcia , 769 m, 19 o 58’14.6’’S, 40 o 32’13.3’’W, 13 November 2011 (st.), M.F. Santos 733 ( SPF!) ; Reserva Biológica Augusto Ruschi , 850 m, 6 December 2001 (fr.), L. Kollmann 5156 ( MBML!) ; Reserva Biológica Augusto Ruschi , 28 November 2001 (fr.), L. Kollmann 5048 ( MBML!) ; Reserva Biológica Augusto Ruschi, 800 m, 27 September 2011 (fl.), L. Kollmann 4776 ( MBML!). Minas Gerais: Mun. Bandeiras , 830–850 m, 15 o 48’23’’S, 40 o 31’5’’W, 30 January 2004 (fr.), W.W. Thomas 13637 ( BHCB!) .

Figures

FIGURE 2. Species distributions. Myrcia ascendens=star; Myrcia attenuata=triangle; Myrcia costeira=circle; Myrcia rupestris=square; Myrcia subterminalis=diamond.

FIGURE 4. Myrcia rupestris. A. habit. B. detail of inflorescence with one basal ramification only. C. floral bud. D. longitudinal section of the flower at anthesis. E. fruit with calyx lobes remnants. Myrcia subterminalis. F. habit. G. floral bud. H. longitudinal section of flower at anthesis. I. fruit with calyx lobes remnants. Vouchers: A–D. Santos 642 (SPF); E. Kawasaki 1021 (SPF); F and G. Rossini 482 (SPF); H. Kollmann 4776 (SPF); I. Kollmann 5156 (SPF).