Coccoloba floresii Ortiz-Díaz & Arnelas, 2015

Ortiz-Díaz, Juan Javier, Arnelas, Itziar, Tun, Juan & Pinzón-Esquivel, Juan Pablo, 2015, Coccoloba floresii (Polygonaceae), a new species from Chiapas (Mexico), Phytotaxa 213 (3), pp. 263-270 : 264-267

Coccoloba floresii Ortiz-Díaz & Arnelas , sp. nov. ( Fig. 1 )

Type: — MEXICO. Chiapas: Municipio Tuxtla Gutiérrez, Parque Nacional Cañón del Sumidero, Mirador La Coyota, 17 km N to Tuxtla Gutiérrez, laderas rocosas de selva baja con Calophyllum , Zanthoxylum , Bursera , Quercus , Ficus y Erythrina , alt. 1320 m, 16° 49’ 06.86’’LN 93° 04’ 08.60’’LO, 23 October 2013, J. J. Ortiz, J. Tun, G. Palma, J. J. Ancona y F. Hernández 2941 (holotype UADY, isotypes CHIP, CICY, MEXU, MO, XAL).

Diagnosis: —Similar to Coccoloba barbadensis Jacq. , differing in lanceolate and acuminate apex leaf blades, longer and glabrous petiole, spicate inflorescence, longer ocreole and shorter fruiting pedicels.

Description: — Trees 6–15 m tall. Branches internodes solid, glabrous, striated, sparsely glandular–punctate, lenticelate, yellowish. Ochrea 4–11 mm long, glabrous, membranous, sparsely glandular–punctate, cylindrical, apex coronate by a reddish nerve, brown or brownish when dry, usually the portion above the nerve of golden colour. Leaves simple, alternate, petiole (5–)11–15(–23) × 1.3–2(–3) mm, glabrous, inserted at base or up to 2 mm above base of the ochrea, striated, sparsely glandular–punctate near the base, brown. Leaf blade (7–)10–15 × 36(–9.5) cm, lanceolate to oblong-lanceolate, subcoriaceous, margins revolute, acuminate at the apex, subcordate to rounded at the base, glabrous above and beneath, hirtellous on the axils of the midvein, and primary veins; venation reticulate with 9–12 primary veins, midvein prominent beneath, brown when dry. Inflorescence terminal, solitary, spicate 10–17(–30) cm long; rachis striate, puberulent, 1–2 mm width; ochreolae (0.7–) 1–1.5 mm long, membranous, pubescent with unicellular hairs, yellowish; bracteolae 1–1.5 mm long, lanceolate, pubescent. Flowers 1–2.2 mm long, solitary or fascicled, sessile or short pedicelled, pedicel when present 0.3–0.7 mm long in fruit, hypanthium 0.8–1 mm long, imbricate aestivation in bud, green to whitish, fleshy; 5 perianth lobes, 1–1.2 mm long, glandular-punctate. Stamens 8–9, (1.8–) 2–2.5 mm long, connate at base, filaments 0.5–2 mm long, subulate; anthers 0.3–0.5 mm long, dorsifixed, yellowish. Ovary 1 mm long, style 3; stigma 3, linear. Fruit achene, trigonous, globose, 6–7(–8) × 4–6 mm, enclosed among the accrescent and fully fused hypanthium and brown, fleshy perianth lobes, these crowned at the apex, crown 0.8–1.1 mm long. Seed with ruminate endosperm.

Eponymy: — The name of the species honors the Mexican botanist José Salvador Flores Guido.

Distribution and ecology:— Coccoloba floresii is a tree growing in cliff faces or disturbed slopes on limestone or sandstone, near streams in tropical dry forests at an elevation of 850–2070 m. ( Fig. 2 ). It is only known from the physiographic regions Central Depression, and Chiapas Plateau ( Müllerried 1957).

Conservation status:—According to the distributional map ( Fig. 2 ), C. floresii mostly occur in the North and Central areas, particularly in the National Park “Cañón del Sumidero” (IUCN & UNEP, category II, WDPA 2014), where one of the authors collected the holotype ( Fig. 3 ), and in the Biosphere Reserve “Selva del Ocote” (IUCN & UNEP, category VI, WDPA 2014). Southwestern populations are rare, and are not included in any protected areas. The available data to assign an IUCN category (2012), is related with B1 criteria. The area of occupancy of the new species is less than 2,000 km 2, suggesting the inclusion of it in “vulnerable” IUCN criteria. However, considering the number of available herbarium material studied, we assumed the presence of more than 10 populations over the distribution range of the new species ( Fig. 2 ). Therefore, we considered that C. floresii is in a “least concern” category. However, more field studies are needed to look for new populations, and to evaluate the possibility of the existence of fragmented populations, especially in southwestern area (because of the stochastic events like fire or human activity). Certainly, field studies will allow us to assess the correct IUCN category ( IUCN 2010).

Observations:—On the basis of the morphological characters, and patterns of geographic distribution, C. floresii appears to be more related to C. barbadensis rather than C. cozumelensis (Table 1). Since the high morphological variability, many taxa have been described in the past for the widespread C. barbadensis , and Howard (1959, 1992) placed them in synonymy. Also misidentifications has been common. Breedlove (1986) in his Flora of Chiapas, cited quite a few collections of Coccoloba barbadensis , C. diversifolia , and C. hondurensis . The following collections formerly included in those species are now as a part of the additional specimens examined of C. floresii : C. barbadensis (Breedlove 13978, 27160, 27508, 49070; Shilom 2742), C. diversifolia (Breedlove 25664, 29701, 44365, 45974, 51909, 51953), and C. hondurensis (Breedlove 30260, 30033). C. floresii differs from C. barbadensis in the shape of the leaf blades (lanceolate and acuminate in the new species vs. obovate to oblong-elliptic with an obtuse apex or short acuminate in C. barbadensis ), the petiole (longer in the new species), the indumentun ( C. floresii is glabrous, while C. barbadensis shows an indumentum scarcely to densely hirtellous with ferruginous trichomes), the inflorescence (spicate in C. floresii , racemose in C. barbadensis ), the ochreole (longer in the new species), and the fruiting pedicels (shorter in C. floresii ). On the other hand, C. floresii also differ from C. cozumelensis by the petiole indumentum, being glabrescent in the new species, and puberulent to scarcely hirtellous in C. cozumelensis ; the leaf blades are markedely longer in the first. Fruit characters are definitve to regard C. floresii as different from C. cozumelensis , because the first have an achene enclosed among the acrescent and fully fused hypanthium and fleshy perianth lobes, crowned at the apex. All fruiting specimens of C. cozumelensis examined so far have an achene enclosed among the hypanthium, and partially fused perianth lobes, free in the upper half.

The three species also differ in their distribution areas ( Fig. 2 ). C. barbadensis occurs in Belize, Guatemala, Honduras, Mexico, and El Salvador. It is frequent in Yucatan Peninsula ( Mexico), appearing as a typical member from lowland savannahs, as well as in semi-deciduous low forest or secondary vegetation, usually on black clay soils along water streams, at an elevation that ranges from 20 to 600 m, being rare at higher altitudes. C. cozumelensis is distributed in a restricted area of Yucatan Peninsula, which includes Mexico (Yucatan, Campeche y Quintana Roo), Belize and Guatemala (Peten). C. cozumelensis grows in tropical dry forests in rendzina soils, at an elevation that ranges from sea level to 400 m, while C. floresii is located exclusively in tropical deciduous forest of the Central Depression, and Chiapas Plateau provinces at higher altitudes that ranges from 850 to 2070 m with a caracteristic habitat of cliff faces or disturbed slopes on limestone or sandstone near streams.

Diagnostic key to Coccoloba barbadensis , C. cozumelensis and C. floresii from Mexico: —A key to distinguish the Mexican species of Coccoloba follows:

1. Leaf blades oblong-obovate to obovate, with obtuse or shortly acuminate apex; indumentum of the petiole sparsely to densely hirtellous with ferrugineous trichomes, (4−)7−12(−20) mm length; inflorescence racemose; fruiting pedicels 1−1.5 mm ............... ..................................................................................................................................................................................... C. barbadensis

- Leaf blades lanceolate to oblong-lanceolate, or narrowly ovate to ovate-lanceolate, with acuminate apex; indumentum of the petiole glabrous or puberulent to densely hirtellous with ferrugineous trichomes, 5−15(−23) mm length; inflorescence spicate; fruiting pedicels 0.3–0.6(−0.7) mm.................................................................................................................................................................2

2. Leaf blades lanceolate to oblong-lanceolate, (7.0−)10.0–15.0(−17.6) × 3.0−6.0(–9.5) cm, with 9–12 pairs of primary nerves; indumentum of the petiole glabrous, (5−)11−15(−23) mm length; ochreolae length (0.7–)1.0− 1.5 mm; achene enclosed among the accrescent and fully fused hypanthium and perianth lobes crowned at the apex............................................................... C. floresii

- Leaf blades narrowly ovate to ovate-lanceolate, (3.0−)4.0−9.0(−11.5) × 2.0−5.0(−6.3) cm, with 7−8 pairs of primary nerves; petiole indumentum puberulent to densely hirtellous with ferrugineous trichomes, 5−8(−14) mm length; ochreolae length 0.5−1.0 mm; achene enclosed among the hypanthium and partially fused perianth lobes free in the upper half.......................................... .................................................................................................................................................................................... C. cozumelensis

Additional specimens examined (paratypes): — MEXICO. Chiapas. Municipio Amatenango del Valle: 12 km al S de Amatenango del Valle, sobre el camino a Villa Las Rosas, 4 September 1984, Cabrera & de Cabrera 7535 ( BM, MEXU). Municipio Berriozabal: near Berriozabal, 2 January 1981, Breedlove 49070 ( CAS, MEXU, MO); Berriozabal a Las Vistas, 17 July 1949, Miranda 5389 ( MEXU); camino a La Pera, 19 May 2010, Sánchez 506 ( CHIP). Municipio Chiapa de Corzo: El Chorreadero, 5.6 miles Southeast of Chiapa de Corzo along Mexican Highway 190, 12 August 1967, Shilom Ton 2742 ( CAS). Municipio Chicoasén: Chicoasén, 7 September 1974, Breedlove 37230 ( CAS, MEXU, MO). Municipio Ocozocoautla de Espinosa: 8 km southwest to international airport (Tuxtla) 21 Jul 1994, Chamé et al. 111 ( CAS); along road to Malpaso, 5 km North of Ocozocuautla de Espinosa, 28 October 1965, Breedlove 13978 ( CAS); along road to Malpaso, 25 June 1972, Breedlove 25664 ( CAS); 3 km North of Ocozocoautla along road to Mal Paso, 19 September 1972, Breedlove 29701 ( CAS, MEXU, MO); idem, 15 December 1972, Breedlove 30260 ( CAS, MEXU, MO); 18−20 km North of Ocozocoautla along road to Mal Paso, 8 December 1972, Breedlove 30033 ( CAS, MEXU, MO); 7 km North of Ocozocuautla, 8 October 1980, Breedlove & Strother 45974 ( CAS); 1 km NW Ocozocoautla-México airport, 19 September 1988, Reyes & Urquijo 990 ( MEXU, MO); Selva del Ocote 32 km northwest of Ocozocoautla, 27 August 1972, Breedlove 27508 ( CAS, MO); Rancho km. 5, road to Malpaso, 8 January 1987, Palacios 191 ( CAS, MEXU); Llano San Juan, Cerrro Meyapac, 20 August 2008, Ruiz 148 ( CHIP); Llano de San Juan above Ocozocoautla NE of the next Tuxtla Gutierrez Airport, 3 November 1979, Breedlove 44365 ( CAS, MEXU, MO). Municipio San Cristobal de las Casas: Santa Cruz en San Felipe, 15 November 1986, Mendez & Martínez 9815 ( CAS, MEXU). Municipio San Fernando: 2 km NE of ejido La Pimienta, brecha del ejido La Pimienta a la cañada El Mojón del Diablo, 5 October 2009, López 968 ( CAS, MEXU); Ribera San José, a 17.3 km de Col. Gabriel Esquinca, 22 May 2009, Martínez 2645 ( CAS). Municipio Socoltenango: near Socoltenango, 3 August 1981, Breedlove 51909 ( CAS, MEXU). Municipio Tenejapa: Jeshab, 15 August 1983, Méndez 6489 ( MO). Municipio Tuxtla Gutiérrez: 16 miles West on Pan American highway, Barranca South of highway, drops sharply, 8 May 1949, Carlson 2071 (F); Mirador La Coyota, 17 km N to Tuxtla Gutiérrez, Cañón del Sumidero, 3 July 1990, Reyes et al., 1736 ( BM, MEXU); El Sumidero, 22 km North of Tuxtla Gutiérrez, 19 August 1972, Breedlove 27160 ( CAS, MO); 21 km N to Tuxtla Gutiérrez, Tepehuaje, 20 November 1989, Soto et al., 13247 ( BM, MEXU); El Zapotal, SE of Tuxtla Gutierrez, 15-Jun 1986, Palacios 108 ( CAS, CHIP, MEXU); idem, 03 July 1991, Palacios 1912 ( CAS, CHIP). Municipio Venustiano Carranza: outskirts of Venustiano Carranza, 23 March 1973, Breedlove 34348 ( CHIP). Municipio Usumacinta: between Soyalo and La Bomba on road to Chicoasen, 10 km west northwest of Soyalo, 7 August 1981, Breedlove 51953 ( CAS, MEXU, MO).

Figures

FIGURE 1. Coccoloba floresii. Drawing based on the holotype. A) Branch and inflorescence axis. B) Detail of indumentum on midvein, and primary veins. C) Ochrea and petiole. D) Portion of the inflorescence, bracteoles, and ochreolae. E) Fruit.

FIGURE 2. Distribution map of Coccoloba barbadensis (triangle), C. cozumelensis (circle), and C. floresii (black square).

FIGURE 3. Coccoloba floresii in the locus classicus. A) Stem and bark. B) Branch, inflorescence, leaves and fruits. C) Inflorescence and fruit. D) Branch, leaves and ochrea.