Wimmeria excoriata J. E. Jimenez & Barrie 2018, sp. nov.
Creators: name: Jiménez, José Esteban
name: Barrie, Fred R.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Celastrales
Celastraceae
Wimmeria
Wimmeria excoriata

description: Wimmeria excoriata J.E. Jiménez & Barrie, sp. nov. (Figs. 1, 2)
Type: — COSTA RICA: Prov. Guanacaste, cantón Bagaces, distrito La Fortuna, Proyecto Río Perdido, 10º36’9’’N, 85º12’18’’W, 223 m, 8 Oct. 2012 (fl, fr), J.E. Jiménez & A. Rojas 989 (Holotype: CR!; isotypes: F!, MO!, USJ!).
Similar to Wimmeria cyclocarpa Radlk. in Donell Smith (1893: 199–200) in having leaves 2–7 cm long, with 4–6 secondary veins per side and tertiary veins that are conspicuously reticulated and pale green to white with a translucent appearance, but differs from that species by its leaves obovate to oblanceolate with the apex rounded, obtuse or retuse (vs. ovate to elliptic with acuminate apex), floral disk 2–2.5 mm in diameter (vs. 1.5–2 mm), fruit smaller, 0.9–1.5 × 1.1–1.7 mm (vs. 1.3–2.0 × 1.6–2.2 cm) and inhabiting dry forests of Costa Rica, Honduras and Nicaragua below 800 m (vs. highlands of NW El Salvador and SE Guatemala, 1000-2100 m.).
Tree 7–15 (–30) m high; young branches minutely and densely villosolous, trichomes 0.2–0.4 mm, erect, white; old branches glabrous or glabrescent. Stem and main branches with smooth and peeling bark. Seedlings with finely linear leaves, 5.2–7 × 0.3–0.5 cm, margin sparsely glandular-toothed. Leaves simple, alternate, 2.5–4.0 (–7.0) × 1.0– 2.5 cm, borne mainly on short lateral branches; stipules minute, caducous; petiole 0.1–0.2 cm, sparsely puberulent to villosolous; blades usually obovate to oblanceolate and rarely elliptic, subcoriaceus, apex usually rounded, obtuse or retuse, base attenuated, upper surface glabrous or sparsely puberulent, lower surface sparsely pubescent to villosolous, especially along the midvein, or glabrescent, trichomes 0.1–0.5 mm; venation penninerved, paler green to white, translucent appearance, secondary veins 4–6 per side, ascending at 60–70º from the midvein, then curving distally, not reaching the margins or the apex; margin crenate, subcrenate or entire. Inflorescences cymose, 2–3 branched, flowers 7–15, sparsely puberulent; peduncle 0.5–0.7 cm; first-order branch ca 0.3 cm, second-order branch 0.2 cm; pedicels 0.4–0.5 cm; bracts minute, 0.5–1.0 mm. Flowers perfect, actinomorphic, bisexual; calyx 5-lobed, lobes subequal, ovate, 0.9–1.1 × 0.8–1.0 mm, green, sparsely puberulent, apex rounded; corolla 5-petalous, the petals ovate to oblongovate, imbricate, 2.3–2.5 × 1.3–1.5 mm, white, entire, apex obtuse to rounded; stamens 5, 2.5–3 mm long, inserted on margin of disk, alternate to petals, filaments filiform, pale green, sparsely puberulent; anthers basifixed, sagittate, 2-celled, 0.5 cm long, white, longitudinally dehiscent; disk annular, 2–2.5 mm diameter, brown, surrounding the ovary, fleshy; ovary submerged in disc, 1.5 mm high, green, style 2 mm long, glabrous, stigma capitate, green, 3-lobe (rarely 2). Fruit a samara, 3 winged (rarely 2), 0.9–1.5 × 1.1–1.5 cm, red or green suffused with red when immature, brown when mature, glabrous, base with calyx and disk persistent, crowned at apex by the persistent style and stigma; wings membranous. Seed 1, linear, 1–1.2 mm, brown.
Distribution and habitat: Endemic to Mesoamerica. It is known from Honduras, Nicaragua and Costa Rica, exclusively distributed in the dry forest, especially in rocky sites and riversides, below 800 m (Fig. 3).
Phenology: Flowering is known between June to October. Fruits have been recorded in May, June and September to December.
Etymology: The specific epithet refers to the peeling bark of the main stem and main branches of the species.
Additional specimens examined: COSTA RICA: Guanacaste: Bagaces, La Fortuna, Centro Turístico Río Perdido, 10º36’9’’N, 85º12’18’’W, 223 m, 15 Feb. 2012 (st), J.E. Jiménez 694 (CR); Bagaces, La Fortuna, San Bernardo, Proyecto Río Perdido, 10º36’9’’N, 85º12’18’’W, 223 m, 14 Jun. 2012 (fl., fr.), J.E. Jiménez 848 (CR, MO, USJ); Bagaces, La Fortuna, San Bernardo, Proyecto Río Perdido, 10º34’35.40’’N, 85º15’8.21’’W, 162 m, 2 Oct. 2013 (fr), J.E. Jiménez & A. Campos 1815 (CR, USJ); Nicoya, Parque Nacional Barra Honda, 10º09’45.14’’, 85º21’29.57’’, 376 m, 8 Jun. 2016 (st), J.E. Jiménez & O. Cubero 3603 (USJ). HONDURAS: Choluteca: Carretera entre de San Francisco y Choluteca, 28 Sep. 1973 (fl), D. Hazlett 956 (MO). Comayagua: Comayagua Valley above San Antonio de Flores, 800 m, 29 Sep.–5 Oct. 1951 (fl, fr), L.O. Williams & R.P. Williams 18273 (DS, EAP [2 sheets], MO, US); Lamaní, Río Grande, 700 m, 18 May. 1984 (fr), B.K. Holst 1773 (EAP). El Paraíso: Valle entre Oreolí y Oropolí, al lado del río Oreolí, 500 m, 4 Nov. 1963 (fr), A. Molina 13216 (EAP, F, LL, NY); Orilla del rio Oropolí cerca de Oropolí, 500 m, 10 Jul. 1961 (fl), A. Molina 10080 (EAP, F, US); Orilla de Quebrada Las Lajas al este de Yuscarán, 700 m, 4 Nov. 1963 (fr), A. Molina 13191 (EAP, F, LL, NY, US); Quebrada Las Lajas entre Yuscarán y Oreolí, 400 m, 16 Jul. 1964 (fl), A. Molina 14565 (EAP, F, LL, NY); El Rodeo, a más o menos 10 km al Sur de la ciudad de Yuscarán, a orilla de carretera a Yuscarán a Oropolí, 500 m, 5 Oct. 1994 (fr), J.L. Linares 1653 (EAP). Francisco Morazán: Tegucigalpa, márgenes del río Las Canoas, ca. 2.5 km cerca de El Tablón, 14°2’N, 87°10’W, 1020 m, 18 Sep. 1996 (fl, fr), J.L. Linares 3510 (EAP); Tegucigalpa, Cerro Las Mesas a 10 km Sur de Tegucigalpa, 1100 m, 14°02’N, 87°12’N, 9 Sep. 2000 (fr), A. Gamero 65 (EAP). Intibucá: Along Ulloa River, 2000 ft, 18–25 Oct. 1980 (fr), D. Day & E. Siegerist 248 (LL, MO). NICARAGUA: Chontales: Cerro La Bateca at Hacienda Veracruz, 8 km S of Cuapa, 12º11’30”N, 200–375 m, 85º22’W, 21 Sep. 1983 (fl), M. Nee 28277 (MO); Hacienda Veracruz, including Cerro La Batea and Cerro Los Charcos, 12º11–12’N, 85º21–22’W, 120–475 m, 4–6 Aug. 1983 (str), W.D. Stevens 22401 (MO); Hacienda Veracruz, including Cerro La Batea and Cerro Los Charcos, 12º11’N, 85º21’W, 120–475 m, 4–6 Aug. 1983 (fl), W.D. Stevens 22384 (CAS, MO); Hacienda Veracruz, including Cerro La Batea, 12º11’N, 86º22’W, 120–375 m, 30 Oct.–2 Nov. 1984 (fr), W.D. Stevens 23323 (CAS, MO, TEX); Hacienda Veracruz, 12º11’N, 85º22’W, 120–140 m, 19 Dec. 1984 (fr), W.D. Stevens 23523 (MO); Hacienda Veracruz, just upriver from ford of Río Pirre, SW of Cerro La Batea, 12º11’23’’, 85º22’28’’W, 95 m, 11 Jun. 2009 (fl), W.D. Stevens & E. Duarte 28403 (MO); Hacienda Veracruz, just upriver from ford of Rio Pirre, SW of Cerro La Batea, 12º11’23”N, 85º21’28”W, 95 m, 24 Jun 2009 (b) W. D. Stevens, et al. 28706 (MO). Estelí: San Juan de Limay, La Rancheria, 13º12’N, 86º30’W, 500 m, 1 Sep 1980 (b), P. Moreno 1934 (MO); 24 km al N de Estelí, 13º16’N, 86º20’W, 700 m, 19 Dic. 1984 (fr), P.P. Moreno 25161 (HNMN, MO); Arrayán, 11 Oct. 1984 (fr), A. Laguna 446 (HNMN, MO). Matagalpa: El Barro, 8 km al SE del poblado de Esquipulas, 12º37’N, 85º51’W, 400 m, 18 Nov. 1984 (fr), P.P. Moreno 25064 (MO, TEX).
Comments: Wimmeria excoriata was identified as W. pubescens in Flora de Nicaragua (Moreno 2011) and by Jiménez (2012) in Costa Rica, a species otherwise known from México (Chiapas and Veracruz) and Guatemala. Wimmeria pubescens can be differentiated by its smaller leaves, 1–2.2 cm long, with 2–3 secondary veins per side running parallel to the margin and the inconspicuous tertiary veins (vs. leaves 2.5–7 cm long with penninerved venation with 4–6 secondary veins per side and conspicuous tertiary veins in W. excoriata).
The peeling bark of this species resembles plants of Plinia L. (1753: 516) and Psidium L. (1753: 470). Because of that, at times it has been confused with guava trees. Seedlings of Wimmeria excoriata have conspicuous and finely linear leaves that change progressively to obovate to oblanceolate, rarely elliptic, as the plant grows, usually when the plant exceeds approximately 30 cm high. This heteroblastic condition has been never documented in the genus before. It could be a diagnostic character for this species alone, or future studies may prove that it also occurs in the seedlings of other species of Wimmeria.
The two populations known from Costa Rica are disjunct and both have between 6 to 10 reproductive individuals. Nothing is known about populations from Honduras and Nicaragua.
The label on A. Gamero 65 (EAP), from Honduras, mentions purple flowers, but the specimen only has fruits and no flowers can be seen. The collector may have confused the structures and treated the red fruits as purple flowers. The specimens J.A. Linares 3510 (EAP) and J.E. Jiménez 848 (CR, MO, USJ) report white flowers (Fig. 2).
description: Published as part of Jiménez, José Esteban & Barrie, Fred R., 2018, A new species of Wimmeria (Celastraceae) from Central America, pp. 229-234 in Phytotaxa 348 (3) on pages 230-233, DOI: 10.11646/phytotaxa.348.3.6, http://zenodo.org/record/13708660