Magnolia sect. Macrophylla, Figlar & Noteboom, 2004

Sánchez-González, Arturo, Gutiérrez-Lozano, Marisol, Yescas, Reyna Domínguez, Hernández-Álvarez, Adriana Gisela, Ortega-Peña, A. Salomé & García, J. Antonio Vázquez-, 2021, Magnolia zotictla (Magnolia sect. Macrophylla, Magnoliaceae): a new species from the southern Sierra Madre Oriental, México, Phytotaxa 513 (4), pp. 271-281 : 279-280

Key to species of Magnolia sect. Macrophylla

1. Mature fruit broadly ovoid to subglobose .........................................................................................................................................2.

- Mature fruit, oblongoid, ovoid or ellipsoid .......................................................................................................................................3.

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 ( United States: AL, AR, GA, KY, LA, MS, NC, OH, TN, and VA).. .................................................................................................................................................................................... M. macrophylla

- Leaves 25.0–35.0(–40.0) cm long; petals 10.0–11.0 cm long; gynoecium 2.0 cm long, stamens 200–220; carpels 30–40; carpel valve margin narrow, 0.2–0.3 cm thick; growing at 1500–1700 m ( Mexico: Nuevo León) .................................. M. nuevoleonensis

3. Carpel beak <0.7 cm ..........................................................................................................................................................................4.

- Carpel beak 1.0– 1.5 cm .....................................................................................................................................................................5.

4. Multi-trunked shrub or lax trees 8.0–10.0 (–12.0) m; fruit cylindrical to ellipsoid; carpels 20–25(–50), growing below 150 m ( United States: Florida) .......................................................................................................................................................... M. ashei

- Single upright trees 8.0–25.0 m; fruit rhomboid-ovoid; carpels 50–65; growing at 800–1950 m ( Mexico)........... M. rzedowskiana

5. Carpels 42–78....................................................................................................................................................................................6.

- Carpels 80–127..................................................................................................................................................................................7.

6. Stamens 192–216, carpels 42–54 ( México: Tamaulipas).............................................................................................. M. alejandrae

- Stamens 308–352, carpels 60–78 ( Mexico: Veracruz) ..................................................................................................... M. vovidesii

7. Fruit dark green to yellow, young fruits glabrescent; stamens 1.9–2.1 cm long; carpels acute to blunt, the tip deciduous ( Mexico: Oaxaca)............................................................................................................................................................................. M. dealbata

- Fruit pinkish-purplish to dark red, young fruit velvety; stamens 1.3–1.8 cm long; carpels acuminate to caudate, the tip sometimes persistent during dehiscence ( Mexico: Hidalgo / Puebla border) ......................................................................................... M. zotictla