Graptopetalum, Rose, 1911

Vázquez-García, J. Antonio, Rosales-Martínez, C. Santiago & Acevedo-Rosas, Raúl, 2022, Graptopetalum trujilloi (Crassulaceae), a new haplostemonous and critically endangered species endemic to western Mexico: comments on taxa of subg. Glassia, Phytotaxa 532 (3), pp. 275-287 : 282-283

Key to the haplostemonous species of Graptopetalum

1. Rosettes 2.0–8.0 cm in diameter, cespitose ........................................................................................................................................2

- Rosettes 9.0–16.0 cm in diameter, non cespitose ...............................................................................................................................3

2. Inflorescence 6.0–12.0 cm long, rosettes 2.0–4.0 cm in diameter, endemic to Colima ....................................................... G. glassii

- Inflorescence 20.0–35.0 cm long, rosettes 6.0–8.0 cm in diameter, endemic to Michoacán ...................................... G. pentandrum

3. Stems more than 10.0 mm in diameter, squamose stem surface ..................................................................................... G. superbum

- Stems less than 8.0 mm in diameter, smooth stem surface ................................................................................................................4

4. Plants 40.0–87.0 cm tall, inflorescence primary branches 5–7, mean flower density per 10 cm of the scape 6–14, flowers per basal branch 7–8, flower diameter 14.9–15.9 mm, petals yellowish with conspicuous transversal red stripes, petal width 2.9–3.0 mm, filaments red, carpels abaxially rounded............................................................................................................... G. rosanevadoense

- Plants 15.0–35.0 (–41.0) cm tall, inflorescence primary branches 8–10, mean flower density per 10 cm of the scape 16–20, flowers per basal branch 3–6, flower diameter 12.9–13.1 mm, petals greenish with inconspicuous transversal red stripes, petal width 2.7–2.8 mm, filaments greenish to distally red, carpels abaxially obtuse.......................................................................... G. trujilloi