Maximum-likelihood phylogeny of A. tonkinensis and 19 related taxa in the family Araceae. Spirodela polyrhiza is used as an outgroup. The scale bar represents the number of substitutions at each locus. Accession numbers: Amorphophallus tonkinensis, PP234804 (this study); Amorphophallus kiusianus, PP072243 (reference not available); Amorphophallus krausei, OR400248 (Yin and Gao 2023b); Amorphophallus konjac, OR438675 (Li et al. 2024); Amorphophallus albus, OM037675 (Shan et al. 2023); Amorphophallus titanium, MN046883 (Henriquez et al. 2021); Amorphophallus kiusianus, PP072243 (reference not available); Amorphophallus yunnanensis, OR400247 (Yin and Gao 2023a); Amorphophallus coaetaneus, OQ404947 (Gao et al. 2023); Caladium humboldtii, ON707032 (reference not available); Xanthosoma helleborifolium, MT161482 (reference not available); Syngonium angustatum, MN046894 (Henriquez et al. 2020a); Alocasia fornicata, MN636779 (reference not available); Leucocasia gigantea, MN972442 (reference not available); Steudnera colocasiifolia, MT161479 (reference not available); Arisaema franchetianum, MN046885 (Henriquez et al. 2020a); Pinellia pedatisecta, MN046890 (Henriquez et al. 2020a); Typhonium blumei, MT872311 (Low et al. 2021); Spirodela polyrhiza, MN419335 (reference not available).