Tabernaemontana riverae L.O. Alvarado & V. Saynes, 2018
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publication ID |
https://doi.org/ 10.11646/phytotaxa.333.2.12 |
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persistent identifier |
https://treatment.plazi.org/id/03FB879A-FFDC-F52B-ACC6-FF2C22F7567D |
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treatment provided by |
Felipe |
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scientific name |
Tabernaemontana riverae L.O. Alvarado & V. Saynes |
| status |
sp. nov. |
Tabernaemontana riverae L.O. Alvarado & V. Saynes View in CoL , sp. nov. ( Fig. 1 View FIGURE 1 , 2 View FIGURE 2 )
The new species is similar to Tabernaemontana eubracteata but differs in its longer elliptic-lanceolate sepals and longer infundibular corollas. Type:— MEXICO. Veracruz: Municipality Hidalgotitlán, Campamento Hermanos Cedillo a 4 km hacia Río Alegre, 150 m, 21 March
1975, Juan & Avendano 15 (holotype: XAL; isotype: MEXU)
Trees or shrubs 1.5–6 m tall, stem terete to subterete, bark smooth or slightly verrucose, fissurate with age, with milky latex. Leaves opposite, pairs subequal, petiolate; petiole 0.5–1.2 cm; blade 5–19 × 1.8–4.5(–8) cm, elliptic, ovate to obovate, base obtuse to acute, apex acuminate, glabrous on both sides, to spreading pubescent beneath, membranaceous, venation brochidodromus, with 10 to 12 pair of secondary veins. Inflorescence 2–4 flowered cymes, terminal, peduncle 2–7 mm, glabrous; bracts 3.5–6.3 × 1 mm, linear to linear-lanceolate, greenish, papyraceous; pedicel 4–8 mm, glabrous; sepals subequal, internals 14.2–18.3 × 3.7–6.2 mm, externals (11.5–) 15–21 × 5.2–7.2 mm, elliptic–lanceolate, acute, glabrous, greenish, with 5–7 veins, persistent in fruit, papyraceous when dried; corolla infundibuliform, yellow to yellowish, glabrous outside, lower tube (13.3–)15–18 × 3.4–5 mm, straight, twisted around the middle in the anther insertion, upper tube 10–14 × 10–15.5 mm, campanulate, suprastaminal appendices or wings present, 15–18 mm long, with a semicircular apical portion, 2–2.5 mm long, pubescent, the tube glabrous above the wings, without thickenings in the mouth of the tube, lobes 15–18 × 14–16 mm, obliquely obovate; stamens included, and inserted halfway up the lower tube, filaments 1.1 mm long, anthers 4.8–5.2 mm long, included, lanceolate, base saggitate, not fused or agglutinated at the top of the style head; Pistil 12–15 mm long, bicarpellary, apocarpous, ovary 1.5–2 × 1.5–2 mm, ovoid, glabrous, ovule numerous, nectary disc present; style 10–13 mm long; style head 1.5–2 mm, capitate. Follicles (2.7–)2.8–4.3 × 1.5–2 cm, obliquely ellipsoid, recurved, apex apiculate, finely striate with 2 evident ridges, non-lenticelated, brownish, glabrous, wall approximately 1.5–2 mm thick; seeds 8.5–9 mm long, oblongoid, striate, with an orange aril.
Additional specimens examined (paratypes): MEXICO. Oaxaca. Along road to Uxpanapa from Sarabia, 220 m, 20 February 1987, Croat & Hannon 65421 ( MEXU). Municipality Matías Romero, 22 km al S de Esmeralda, 9 km al S del Aserradero La Floresta, lomas al S del Río Verde, 290 m, 26 March 1981, Wendt, Villalobos, Navarrete & Anguiano 3073 ( MEXU).
Tabasco: Municipality Huimanguillo, entrada del ejido Villa de Guadalupe, viniendo de la Colonia Las Flores, 260 m, 5 April 1998, Guadarrama, Ortiz, Gómez & Flores 6317 ( MEXU).
Veracruz: Municipality Hidalgotitlán, Campamento Hermanos Cedillo a 4.5 km por la escuadra, 150 m, 2 April, 1975, Ortíz & Martiniano 80 (MEXU). Km 8–12 del camino Plan de Arroyo-Álvaro Obregón, 140 m, 18 April 1974, Dorantes & Castillo 2872 (XAL). Km 0–25 del Campamento Hermanos Cedillo, camino hacia Río Alegre, desviación al E., 22 April 1974, Dorantes & Castillo 2951 (XAL). Municipality Minatitlán, 6.6 km al Norte de la terracería La Laguna-Río Grande, sobre el camino nuevo (no completo) a Ejido Belisario Domínguez, el cual sale de la terrracería 14.7 km al E de la Laguna, 130 m, 13 July 1980, Wendt & Villalobos 2554 (MEXU). Zona Uxpanapa, a 13.7 km al E de La Laguna sobre terracería a Uxpanapa, luego 5–7 km al N, 130 m, 29 March 1982, Lorence, Wendt, Riviere, Vázquez, Ton & Navarrete 3972 (MEXU, XAL). 13.7 km al E de la Laguna, sobre terracería a Uxpanapa, luego 8 km al N sobre camino nuevo (no completo) a Belisario Domínguez, 130 m, 21 March 1981, Wendt & Villalobos 3018 (MEXU). Municipality Uxpanapa, Esfuerzo Nuevo, al E cerro Cordón Platanillo, 255 m, 3 May 1996, Rivera & Escobedo 92 (MEXU).
Habitat:— Tabernaemontana riverae grows in evergreen tropical forest and is associated with Brosimum alicastrum Swartz (1788: 12) and members of Bursera Jacquine ex Linneaus (1762: 471) , Anacardiaceae , Lauraceae and Clusiaceae . The species grows in drained soil on rocky hills between 130–290 m elevation in the Gulf of Mexico south of Veracruz and east of Oaxaca, receiving more than 2000 mm of annual rain with a median annual temperature between 26 and 30º Celsius ( INEGI 2014, 2015, 2016).
Distribution:—The new species of Tabernaemontana is endemic to Mexico and is only known from the states of Oaxaca, Tabasco, and Veracruz, growing on the slopes of the Mexican Gulf and the Isthmus of Tehuantepec.
Etymology:—The specific epithet is dedicated to Diego María de la Concepción Juan Nepomuceno Estanislao de Rivera y Barrientos Acosta y Rodríguez, who is better known as Diego Rivera . He was a social activist and one of the most important muralists in Mexico. Diego’s themes included the social conflicts of pre- and post-revolutionary Mexico, pre-Hispanic legacy, and science communication and popularization ( Mandel 2007, Souter 2007). In his mural “ Man, Controller of the Universe ” ( Figs. 3A–B View FIGURE 3 ), Rivera painted Charles Darwin and the idea that regardless of the repercussions of science and technology in our world, we are connected with all other organisms on the planet ( Eldredge 2005). In the Sump of Dolores, he painted the mural “ Water, origin of life ” ( Figs. 3C–D View FIGURE 3 ), which is inspired by the scientific works of biochemist Alexander Oparin and biologist Ernst Haeckel ( Lazcano 2012).
Common names:—The local names of this species include “cojón de chivo”, “cojón de burro” or “lechería”. These names are often used to refer to many other species of Apocynaceae trees.
Conservation status:— Tabernaemontana riverae is only known from a few localities in three states. Given that the new species is only found in small areas of Oaxaca, Tabasco, and Veracruz, and that the intense grazing activity that occurs in Tabasco and Veracruz ( Pérez et al., 2005) can significantly reduce the number of individuals in the future, we suggest adding the species to the Vulnerable (VU B2, C) category based on IUCN criteria ( IUCN 2013).
Taxonomic remarks:— Tabernaemontana is well represented in Mexico with 15 species registered, of which six are endemic. These numbers highlight the diversity of the genus in the country. Tabernaemontana riverae is morphologically similar to T. eubracteata , T. hannae (M. Méndez & J.F. Morales 2005:354) A.O. Simões & M.E. Endress (2010:787) , and T. robinsonii ( Woodson 1928:369) A.O. Simões & M.E. Endress (2010:787) . All these taxa share a similar sepal morphology, that is foliose, persistent in fruit, and typically with conspicuous venation. In addition, some of the species share the same infundibular corolla morphology ( Fig. 4 View FIGURE 4 ).
The new species was previously determined as T. eubracteata but can be separated from this species based on its infundibuliform corolla (vs. slightly infundibuliform), sub-equal and elliptic–lanceolate sepals (vs. clearly unequal and lanceolate) and distribution below 300 m asl (vs. above 500 m asl). Tabernaemontana riverae and T. hannae share long sepals that become papyraceous when dried, but the former is easily distinguished by its sepals elliptic-lanceolate (vs. lanceolate to ovate-lanceolate in T. hannae ) and corollas infundibuliform (vs. salverform to slightly urceolate in T. hannae ). Finally, the new species can be separated from T. robinsonii , based on its sepals with conspicuous veins (vs. inconspicuous in T. robinsonii ), its corolla size of 2.3–3.2 cm length (vs. 3–5 cm length in T. robinsonii ), its abrupt campanular upper tube (vs. slightly conical in T. robinsonii ) and its distribution in Mexico (vs. Central America).
holotype specimen (D), T. eubracteata specimen of J.C. Soto 8433 (E) and holotype specimen (F). Scale bar, 2 cm.
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