Evan,
Even though I am a scientist and am very familiar with keying out plants, my method of identifying plants is strictly intuitive and in practice, I have IDd plants and insects with far more accuracy and speed than anyone can do with a key. Consequently, I am not well versed in the available keys for aroid genera because I use them only rarely. My work with hybridizing has even led me to question the classification of some aroids. Some aroid genera are refractory to keying because of the number of natural cultivars. Xanthosoma could be one of these.
LariAnn
