Monteverdia multicostata Cornejo & Biral, 2021

Biral, Leonardo & Cornejo, Xavier, 2021, Two new species of Monteverdia (Celastraceae) from Ecuador, Phytotaxa 479 (2), pp. 183-190 : 184

Monteverdia multicostata Cornejo & Biral , sp. nov. ( Figs. 1 and 2 )

Type:— ECUADOR. Manabí: La Esperanza, secondary wet forest, 0°22´30.2¨ S 79 ° 36´19.2¨ W, 200 m, 21 February 2020 , Cornejo & Loor 9320 (holotype GUAY, isotype QCA) .

Species insignis ab omnibus speciebus notis generis fructibus grandioribus et seminibus multicostatus differt.

Tree, 8–30 m tall, to 80 cm in diameter at breast height, glabrous; inner bark red, outer bark richly lenticellate, gray with irregular white spots; old twigs cylindrical, blackened (dry); young twigs slightly flattened, grayish (dry), densely lenticellate, lenticels whitish and prominent. Leaves alternate, distichous; stipules not seen, early caducous; petiole ca. 5 mm long, slightly flattened, drying black; blades 7–14 × 4–6 cm, elliptic to obovate, chartaceous, base cuneate to obtuse, margin entire, flat, apex acute to obtuse, acuminate, glabrous, drying brown on both faces; venation brochidodromous, primary vein plane on the adaxial face, slightly prominent at the base, raised slightly on the abaxial face, secondary veins 7–9 pairs, darker on the adaxial face, slightly raised or impressed on the abaxial face. Inflorescences fasciculate, simple, axillary, multi-flowered; pedicels ca. 7–8 mm long, cylindrical; bracteoles acute, 2 mm long, margin irregular. Flowers 5-merous, prefloration imbricate, in one row with the margins of one petal overlapping two other petals, three petals with one margin external and the other internal, and one petal with both margins completely internal; calyx gamosepalous at base, lobes ca. 1 × 0.8 mm, green, ovate to deltoid, margin sparsely ciliate, blackened; corolla dialypetalous; petals 2–3 × 1 mm, light-green, ovate, broadly divergent to subpatent at anthesis, apex obtuse to rounded, margin membranous, hyaline, slightly undulate; stamens 5, alternate with petals, 1–1.5 mm long, filaments flattened, broadened at base, attenuate at apex, inserted on the margin of the disk, erect and becoming reflexive at anthesis; anthers ovoid, brown when mature, dorsifixed, dehiscing longitudinally; disk intrastaminal, 2 mm in diam., pentagonal, green, blackened when dry, margin slightly undulate; gynoecium 2-carpellate, ovary fused to disk, style evident, stigma simple. Fruit a loculicidal capsule, 25–35 × 18–25 mm, obovoid to narrowly-obovoid or ovate, base cuneate to narrowly-cuneate, apex rounded, style not persistent, pericarp coriaceous, ca. 0.8–1.2 mm thick, green when unripe, light-green to yellowish when ripe and brown when dry, opening by 2 valves; seeds 1–2(–3), 1.8–2.5 × 1.0– 1.5 mm, oblong to ellipsoid, ridged, with 6–14 conspicuous ridges, evenly arranged in the longitudinal, completely surrounded by a sweet white aril, maturing brown to black, glossy when dry.

Phenology. Flowering in February; fruiting in February to May.

Etymology. The specific epithet of this species is a reference to the uncommon morphology of the seeds, with multiple longitudinal ridges, a unique feature among the known species of the genus.

Distribution and habitat. Monteverdia multicostata occurs in the lowland wet forests of Manabí and Esmeraldas provinces, in northwestern Ecuador from 200 to 600 m in elevation.

Vernacular name: Carne de pardis (tinamou) (Clark 4848)

Biological interactions and uses. The sweet aril is eaten by: humans, howler monkeys, Alouatta palliata ; spider monkeys, Ateles fusciceps ; machín, Cebus capuchinus ; cusumbo, Potos flavus ; and large birds such as toucans ( Rhamphastidae ) from the type locality (Anelio Loor pers. comm.). The recorded vernacular name (op. cit.) suggests that the aril of fruits is also eaten by tinamou ( Tinamus sp. ).

Conservation status. The conservation status of Endangered is recommended for Monteverdia multicostata , based on the IUCN (2012) criteria ( EN B 1ab[iii]). Ongoing deforestation in northwestern Ecuador is leading to fragmentation and degradation of habitat with small forest patches becoming extinct. Monteverdia multicostata has not been recorded within the National System of Protected Areas of the country ( PANE).

Notes. The new species is easily characterized by the multi-ridged seeds. This feature is unique within all known species of Monteverdia , with all other known species possessing smooth to slightly rugose seeds. The large fruits are also distinct. Only one other species in the genus, M. fugax ( Biral & Lombardi 2016: 99) Biral in Biral et al. (2017: 688), has fruits of similarly large dimensions, however, M. fugax is endemic to the Brazilian Atlantic Rainforest and produces reduced cymes, rather than the fasciculate inflorescences found in most Monteverdia species.

Additional specimens examined (paratypes): ECUADOR. Esmeraldas : Quinindé. Bilsa Biological Station. Mache mountains, 35 km W of Quinindé, 5 km W of Santa Isabel. Forest along Dogala trail, 2 April 1995, Clark & Troya 568 ( MO, QCNE, US [two sheets]); Ibidem, 5 km W of Santa Isabel. Third lot W of Station following road towards Piedrita, 13 May 1995, Clark & C. Watt ( F, MO, QCNE, US [two sheets]); Ibid., 35 km W of Quinindé , 20 March 1998, Clark & Pallis 4848 ( MO, QCNE, US) .

Figures

FIGURE 1. Monteverdia multicostata: A. Lenticellate branch bearing fasciculate inflorescences. B. Terminal leafy branch and fruits. C. Leafy branches bearing yellowish mature erect fruits. D. Greenish mature open fruit displaying a white-arillate seed. E. Longitudinally ridged, cacao-like seeds. F. Bark.A, C, courtesy of Bruno Baumann, from unvouchered specimens in Esmeraldas province. B, D–F, from the type Cornejo & Loor 9320 (GUAY).

FIGURE 2. Monteverdia multicostata: A. Fruiting branch. B. Seed. C. A ripe open fruit. A-C, from Cornejo & Loor 9320 (GUAY). Drawings by André Moura Pedroso.