Corncob flower, Magnolia mixteca (M. sect. Macrophylla, Magnoliaceae) a new species endemic to the Alto Balsas Basin (Baja Mixteca), in the Pacific slopes of Oaxaca, Mexico Author Vázquez-García, J. Antonio 0000-0002-8393-5906 Herbario IBUG, Instituto de Botánica, Departamento de Botánica y Zoología, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, km. 15.5 carr. Guadalajara-Nogales, Las Agujas, Zapopan, Jalisco, 45221, México & talaumaofeliae @ gmail. com; https: // orcid. org / 0000 - 0002 - 8393 - 5906 talaumaofeliae@gmail.com Author Yescas, Reyna Domínguez 0000-0002-4169-6871 Herbario IBUG, Instituto de Botánica, Departamento de Botánica y Zoología, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, km. 15.5 carr. Guadalajara-Nogales, Las Agujas, Zapopan, Jalisco, 45221, México & reyna. dominguezy @ gmail. com; https: // orcid. org / 0000 - 0002 - 4169 - 6871 reyna.dominguezy@gmail.com Author Luna-Vega, Isolda 0000-0002-7243-9018 Laboratorio de Biogeografía y Sistemática, Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico & luna. isolda @ gmail. com; https: // orcid. org / 0000 - 0002 - 7243 - 9018 luna.isolda@gmail.com Author Rodríguez-Ramírez, Ernesto C. 0000-0001-6206-8615 Laboratorio de Biogeografía y Sistemática, Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico & echanes @ ciencias. unam. mx; https: // orcid. org / 0000 - 0001 - 6206 - 8615 echanes@ciencias.unam.mx Author Rodríguez-Pérez, Ciro 0000-0003-4892-1629 Herbario IBUG, Instituto de Botánica, Departamento de Botánica y Zoología, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, km. 15.5 carr. Guadalajara-Nogales, Las Agujas, Zapopan, Jalisco, 45221, México & ciro. biologo @ gmail. com; https: // orcid. org / 0000 - 0003 - 4892 - 1629 ciro.biologo@gmail.com text Phytotaxa 2021 2021-10-11 522 3 200 210 http://dx.doi.org/10.11646/phytotaxa.522.3.3 journal article 4079 10.11646/phytotaxa.522.3.3 35c11603-3013-4807-9fd8-2c6692f25d8f 1179-3163 5560401 Key to species of Magnolia sect. Macrophylla 1. Mature fruit broadly ovoid, broadly ellipsoid to subglobose ............................................................................................................2. – Mature fruit oblongoid, ovoid or ellipsoid ........................................................................................................................................4. 2. Leaves 50–110 cm long; petals 20 to 23 cm long; gynoecium 4 cm long; stamens (300–)350–580; carpels (44–)50–80; carpel valve margin wide, 0.4–0.5 (–0.7) cm thick; growing at 150–300 m ( US : AL, AR, GA, KY, LA, MS, NC, OH, TN, and VA) .................. .................................................................................................................................................................................... M . macrophylla – Leaves 25.0–35.0(–40.0) cm long .....................................................................................................................................................3. 3. Petals 10.0–11.0 cm long; carpels 30–40; elev. 1500–1700 m ( Mexico : Nuevo León )......................................... M . nuevoleonensis – Petals 12–15 cm long, carpels 58–62; elev. 1800– 220 m ( Mexico : Oaxaca ).................................................................... M . mixteca 4. Carpels shortly (< 0.7 cm ) beaked......................................................................................................................................................5. – Carpels prominently (1.0– 1.5 cm ) beaked ........................................................................................................................................6. 5. Multi trunked large shrub, or small leaning trees 8.0–10.0 (–12.0) m; fruit cylindrical to ellipsoid; carpels 20–25(–50), shortly beaked; elevation less than 150 m ( US : Florida ).................................................................................................................... M . ashei – Single upright tall trees 8.0–25.0 m; fruit rhomboid-ovoid; carpels 50–65; elevation 800–1950 m ( Mexico : San Luis Potosí , Querétaro & Hidalgo )............................................................................................................................................... M . rzedowskiana 6. Carpels 42–78....................................................................................................................................................................................7. – Carpels 80–127..................................................................................................................................................................................8. 7. Stamens 192–216, carpels 42–54 ( Mexico : Tamaulipas ).............................................................................................. M . alejandrae – Stamens 308–352, carpels 60-78 ( Mexico : Veracruz )...................................................................................................... M . vovidesii 8. Fruit dark green to yellow, young fruits glabrescent; stamens 1.3–1.8 cm long; carpels acute to blunt, tip deciduous ( Mexico : Oaxaca )............................................................................................................................................................................. M. dealbata – Fruit pinkish purplish to dark red, young fruit velvety; stamens 1.9–2.1 cm long; carpels acuminate to caudate, tip sometimes persistent at dehiscence ( Mexico : Hidalgo / Puebla border) ................................................................................................. M . zotictla