Key to Mexican species of Magnolia section Talauma

1 Flower buds 2.5–4.5 cm long ........................................................................................................................................................... 2

– Flower buds 5.0–12.0 cm long ......................................................................................................................................................... 3

2 Carpels 8–9; mature leaf petioles 5.2–7.2 cm; Chimalapas, Oaxaca ...................................................................... M. chimalapana

– Carpels 19–28: mature leaf petioles 2.5–4.0 cm; Uxpanapa, Veracruz ............................................................................. M. wendtii

3 Abaxial portions of carpels detaching from the fruit axis mainly in large irregular masses of many carpels (> 15) ...................... 4

– Abaxial portions of carpels detaching from the fruit axis usually singly or occasionally in groups of few carpels (<8) ................ 5

4 Fruit ellipsoid-subglobose, 10.4–14.8 × 7.9–9.2 cm, carpels 89–92, Selva Zoque, Chiapas .................................. M. perezfarrerae

– Fruit spheroidal, 6 cm in diam., carpels 36–42, Selva Chimalapas, Oaxaca ................................................................ M. heribertoi

5 Leaves lanceolate to broadly lanceolate ........................................................................................................................................... 6

– Leaves elliptical to obovate .............................................................................................................................................................. 7

6 Carpels 20–28, 1.8–3.75 × 1.7–2.1 cm, carpel lateral walls curved outwards and wing-like, Los Tuxtlas ........................................ ....................................................................................................................................................................... Magnolia sinacacolinii

– Carpels 30–35, 3.4–5.0 × 1.7–2.1 cm, carpel side walls not curved outwards, Los Tuxtlas ..................... Magnolia lopezobradorii

7 Leaves obovate ................................................................................................................................................................................. 8

– Leaves elliptical ................................................................................................................................................................................ 9

8 Carpels 57–59, Uxpanapa-Las Choapas, Veracruz .................................................................................................... M. uxpanapana

– Carpels 30-40, San Pedro Ixcatlán, Oaxaca ................................................................................................................... M. decastroi

9 Petals adaxially with purple stains ................................................................................................................................................. 10

– Petals adaxially white ..................................................................................................................................................................... 11

10 Fruit ovoid to oblongoid, N Puebla, NW Oaxaca and central Veracruz ........................................................................ M. mexicana

– Fruit subglobose; Santa Martha volcano, Veracruz ............................................................................................ M. zoquepopolucae

11 Fruits ovoid to obovoid or ellipsoid ............................................................................................................................................... 12

– Fruits globose to subglobose or broadly ovoid ............................................................................................................................... 14

12 Flowers 20 to 22 cm in diam., fruits ellipsoid, basal carpels decurrent 0.4 to 0.6 cm; Sierra de Manantlán, Jalisco and Colima ..... ......................................................................................................................................................................................... M. jaliscana

– Flowers 13 to 17 cm in diam.; fruit pear-shaped to ovoid; basal carpels decurrent to 1.0–2.0 cm; outside Sierra de Manantlán, Jalisco and Colima .......................................................................................................................................................................... 13

13 Leaves 35–45 × 23–29 cm, flower 13–14 cm in diam., carpel apex cleft (1/3–1/2); only recorded from Talpa de Allende, Jalisco. ............................................................................................................................................................................................ M. ofeliae

– Leaves 18–38 × 8–23 cm; flower 16-17 cm in diam.; carpel cleft apically (2/3–3/3), S Oaxaca ............................. M. macrocarpa

14 Carpels 61–70, indistinctly marked; seeds scarlet; Lacandona, Chiapas .................................................................. M. lacandonica

– Carpels 36–41, conspicuously marked; seeds orange to pale red; N Oaxaca ............................................................... M. yajlachhi