Tabernaemontana riverae L. O. Alvarado & V. Saynes 2018
Creators: name: Alvarado-Cárdenas, Leonardo O.
name: Lozada-Pérez, Lucio
name: Cadena, Joselin
name: Hernández, Sofia Islas-
name: Martínez-González, C. Ramiro
name: Cortez, Ericka B.
name: González- Martínez, César A.
name: González-Ramírez, Ixchel S.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Gentianales
Apocynaceae
Tabernaemontana
Tabernaemontana riverae

description: 15. Tabernaemontana riverae L.O. Alvarado & V. Saynes (2018:275–277). (Fig. 2, 3).   
 Type:— MEXICO. Veracruz: Municipio 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. Petioles 0.5–1.2 cm long; blades 5–19 × 1.8–4.5(8) cm, membranaceous, elliptic, ovate to obovate, base obtuse to acute, apex acuminate, margin entire, glabrous on both sides, to spreading pubescence abaxially. Inflorescence 2–4 flowers, peduncle 2–7 mm long; bracts 3.5–6.3 mm long, linear to linear-lanceolate, papyraceous; pedicels 4–8 mm long; sepals equal to subequal, 1.4–2.1 × 0.4–0.7 cm, elliptic-lanceolate, acute, glabrous, conspicuous venation; corolla infundibuliform, yellow to yellowish, lower tube (1.3–)1.5–2.2 × 0.3–0.5 cm, twisted around the anthers, staminal ridges present, upper tube 1.0–1.4 × 1.0– 1.5 cm, campanulate, suprastaminal corona of five wing-shaped lobes present, opposite the anthers, along the tube, limb lobes 1.5–1.8 × 1.4–1.6 cm, obliquely obovate; stamens inserted near of middle of the lower tube, anthers 4.8–5.2 mm long, included, yellow; pistil 1.2–1.5 cm long, nectary present. Follicles (2.7–)2.8–4.3 × 1.5–2 cm, obliquely ellipsoid, recurved, short apiculate, finely striate and with 2 lateral ridges, not lenticelate, brownish, glabrous; seeds 8.5–9 mm long.   
 Habitat and phenology: —Evergreen forest and secondary vegetation, with an altitudinal range of 130–300 m a.s.l. Flowering and fruiting from February to July.   
 Distribution: —Endemic to Mexico in the states of Oaxaca and Veracruz (Fig. 6b).   
 Conservation status: — Endangered (EN). Tabernaemontana riverae is restricted to a few known localities in the states of Oaxaca and Veracruz (Fig. 6b). The area covered, according to its EOO of 2,023 km 2 and AOO of 40 km 2, is less than 1% of the area of Mexico (Table 3); its populations are scarce, and grazing and building activities may significantly reduce the number of individuals in the future, mainly in Veracruz, which has significant deforestation rates (Pérez et al. 2005). We suggest the category of endangered for this species.   
 Additional specimens examined:— MEXICO. Oaxaca: Mun. Matías Romero, 22 km al S de Esmeralda 9 km al S del Aserradero La Floresta, lomas al S del Río Verde, 290 m a.s.l., 26 Mar 1981, Wendt 3073 (MEXU); Veracruz: Mun. Hidalgotitlán, Campamento Hermanos Cedillo a 4.5 km por la escuadra, 150 m a.s.l., 2 Apr 1975, Ortíz 80 (MEXU); Km 8–12 del camino Plan de Arroyo-Álvaro Obregón, 140 m a.s.l., 18 Apr 1974, Dorantes 2872 (XAL); Km 0–25 del Campamento Hermanos Cedillo, camino hacia Río Alegre, desviación al E, 22 Apr 1974, Dorantes 2951 (XAL). Mun. Jesús Carranza, A 2 km N del poblado 2. Ejido F. J. Mina, 120 m a.s.l., Vázquez V-2378 (MEXU); Mun Minatitlán, 6.6 km al Norte de la terracería La Laguna-Río Grande, sobre el camino nuevo a Ejido Belisario Domínguez, el cual sale de la terracería 14.7 km al E de la Laguna, 130 m a.s.l., 13 Jul 1980, Wendt 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 a.s.l., 29 Mar 1982, Lorence 3972 (MEXU, XAL); 13.7 km al E de la Laguna, sobre terracería a Uxpanapa, luego 8 km al N sobre camino nuevo a Belisario Domínguez, 130 m a.s.l., 21 Mar 1981, Wendt 3018 (MEXU); Mun. Uxpanapa, along road to Uxpanapa from Sarabia, 220 m a.s.l., 20 Feb 1987, Croat 65421 (MEXU). Esfuerzo Nuevo, al E cerro Cordón Platanillo, 255 m, 03 May 1996, Rivera 92 (MEXU).   
 Common names and uses: —In Veracruz “cojón de burro”, “cojón de chivo”, and “lecherillo”.   
 Notes: — Tabernaemontana riverae is morphologically similar to T. eubracteata due to the foliose sepals, which are typically persistent with conspicuous venation, and infundibuliform corolla (Fig. 2), but can be separated by its infundibuliform corolla with upper tube 1.0–1.4 × 1.0– 1.5 cm (vs. slightly infundibuliform with upper tube 0.3–0.65 × 0.6–0.8 cm), its sepals 1.4–2.1 cm long, elliptic-lanceolate (vs. sepals (0.5) 0.8–1.0 cm long, ovate to ovate-lanceolate) and its distribution below 300 m a.s.l. (vs. above 500 m a.s.l.).
description: Published as part of Alvarado-Cárdenas, Leonardo O., Lozada-Pérez, Lucio, Cadena, Joselin, Hernández, Sofia Islas-, Martínez-González, C. Ramiro, Cortez, Ericka B., González- Martínez, César A. & González-Ramírez, Ixchel S., 2019, The triad of knowledge: Systematic, diversity and conservation status of the Mexican species of Tabernaemontana (Apocynaceae; Rauvolfioideae: tribe Tabernaemontaneae), pp. 1-46 in Phytotaxa 388 (1) on pages 35-36, DOI: 10.11646/phytotaxa.388.1.1, http://zenodo.org/record/13725393