Pimenta berciliae T. Vasc. & B. Peguero, 2018

Vasconcelos, Thais N. C., Lucas, Eve J. & Peguero, Brigido, 2018, One new species, two new combinations and taxonomic notes on the All-spice genus Pimenta (Myrtaceae) from Hispaniola, Phytotaxa 348 (1), pp. 32-40 : 34-37

1. Pimenta berciliae T. Vasc. & B. Peguero sp. nov. ( Figures 2 and 3 ).

Type:— DOMINICAN REPUBLIC. Santo Domingo: Jardín Botánico Nacional Dr. Rafael Ma. Moscoso, 18°29’32.2”N, 69°57’29.4”W 10 Apr. 2015 (b, fl), T. N. C. Vasconcelos 576 (holotype JBSD!; isotype K!) .

Pimenta berciliae is easily identifiable in flower by the unilocular ovary and pentamerous flowers. Even though these characters are found in other Pimenta species [e.g. pentamerous P. haitiensis ( Urban, 1921: 404) Landrum (1984: 242) and unilocular P. cainitoides ( Urban, 1924: 301) Burret (1941: 514) ], this combination is unique to the new species.

Tree to 7m high. Young twigs glabrous, light green, flattened and keeled, becoming brown-red and terete at maturity. Trunk reddish brown, bark smooth and somewhat papery-flaky. Leaves opposite to subopposite petiole to 0.6cm long. Blades lanceolate, 5.9–9.3 × 2.1–3.8 cm, slightly discolorous, bright-dark green becoming gray adaxially when dried, light green on the abaxial side, coriaceous, both surfaces punctuate and glabrous, entire margin slightly revolute in fresh material, undulatingin dry material, apex acute, slightly atenuate on apical leaves, base cuneate. Secondary veins 4–7 mm apart, 12–16 pairs per blade, held at an angle of c. 60° relative to the midvein; marginal vein c. 1.5mm from the margin at the mid point, tertiary veins conspicuous; mid vein canaliculate adaxially, keeled abaxially. Inflorescence a simplified panicle, 3–7 cm long, subterminal, rachis mostly glabrous, with white-grayish simple trichomes on the apical portion and in the axils of branches; branches subopposite terminating in dichasia. Bracteoles linear, 2–3mm, caducous before flower anthesis; floral bud clavate, constricted between the ovary and hypanthium, mature buds to 5mm long, densely covered in white hairs. Hypanthium slightly extended above ovary summit, internally and externally pubescent. Perianth free, 5-merous. Sepals brownish green, sometimes dark gray in dried material, dentate, opening to a star shape at anthesis, lobes 2.0–2.5 × 2.0– 2.5 mm, apex acute, base truncate, internally and externally covered in white hairs. Petals white, obovate, reflexed at anthesis; externally pubescent, internally mostly glabrous, apex rounded, base truncate, 2.0–2.5 × 4.0– 4.5 mm. Staminal ring pubescent, 1.0– 1.5mm wide, stamens ca. 100, 2.5–3.0mm, anthers 0.5–0.6mm; style 4.5–4.8mm long, filiform, ovary unilocular, free apical placentation, ca. 10 ovules. Fruits subglobose, 5–8 mm in diameter with persistent calyx lobes, covered in white-grayish hairs and purple when mature. A single seed, brown to black and subglobose. Embryo not seen.

Habitat and phenology:—The type collection comes from a cultivated specimen growing in the Jardín Botánico Nacional in Santo Domingo, Dominican Republic. Specimens collected at the natural population area (paratypes here designated) show that Pimenta berciliae occurs in montane humid forests and on calcarious soil. Pimenta berciliae was collected with buds and flowers in April and with fruits in June.

Molecular information:—Sequences for the type specimen are deposited in GenBank under the accession numbers MF954067 (ITS), MF954323 (psb A- trn H), MF954373 (rpl 16), MF954235 (rpl 32- trn L), MF954186 (trn Ltrn F), and MF954126 (trn Q- rps 16).

Conservation:—Natural populations are restricted to a small area in Samaná and Cordillera Septentrional (red circles, Figure 1A ). Preliminary conservation status according to IUCN’s Extent of Occurrence criteria ( IUCN, 2012; EOO = 132.838 km 2) indicates an Endangered species.

Etymology:—The epithet post humously honors Bercilia Peguero, mother of Brígido Peguero, one of the authors of this species, in recognition and gratitude to those who strove to establish a united, honest, supportive and responsible family.

Paratypes:— DOMINICAN REPUBLIC. Province of Hermanas Mirabal ; Salcedo, 19°27’7.27”N, 73°25’0.01”W, March 2009 ; R. Rodríguez 296 (JBSD!); Salcedo, 19°26’49.42” N, 70°25’1.38”W, March 2009, R. Rodríguez 339 ( JBSD!) ; Tenares , 19°31’11”N, 70°20’12”W, February 2001, A. Veloz 2335 ( JBSD!). Province of Puerto Plata ; Sosúa , 19° 43.1’ N, 70° 26.9’ W, June 2017, T. Clase 10164 ( JBSD!) .

Affinities and discussion:— Pimenta berciliae is compared in the diagnosis with P. haitiensis and P. cainitoides , since it bears a combination of characters which occur separately in these species. Additionally, it is also distinct from other Hispaniola species of Pimenta in its few flowered panicles, relatively large flowers and lanceolate leaves that resemble those of P. guatemalensis ( Lundell, 1968: 42) Lundell (1971: 159) , endemic to continental Central America; its bud and floral morphology also superficially resembles that of the distantly related Pimenta pseudocaryophyllus ( Gomes, 1812: 92) Landrum (1984: 242) (by the large size of buds and flowers). Its phylogenetic position, however, indicates a close relationship with the sympatric Pimenta yumana ( Figure 1B ). With the latter, Pimenta berciliae shares the reduced number of flowers in the inflorescence.

Figures

FIGURE 1. Distribution and phylogenetic position of treated species within Pimenta. (A) Natural distributions of Pimenta berciliae (red circles); P. yumana (yellow triangle) and P. samanensis (yellow star). (B) An extract from the Myrteae phylogeny (see Vasconcelos et al., 2017 for methodology) based on maximum likelihood analysis of two markers (ITS and psbA-trnH; see Appendix 1 for Genbank accession codes) showing phylogenetic positions of Pimenta berciliae and Pimenta yumana. Bootstrap values above 90 are given at each node.

FIGURE 2. Field pictures and details of Pimenta berciliae (A–H). (A) Fertile branch with subterminal inflorescence; (B) Leaves with slightly revolute margins; (C) Reddish brown bark, somewhat papery-flaky; (D) Adaxial and (E) abaxial leaf surfaces, showing color difference between surfaces in fresh material. (F) 3-flowered inflorescence with slightly assymetrical lateral branching; (G) Old flower with stamens only partially present showing reflexed petals; (H) Frontal view of old flower remains (without stamens or petals) showing the five calyx lobes and the pentagonous hypanthium.

FIGURE 3. Isotype image of Pimenta berciliae at K.