cuauhzahuatl.

CUAUHZĀHUA-TL pl: -MEH casaguate, a tree popularly belived to be poisonous to people and animals (Ipomoea murucoides, Ipomeoa arborescens) / cazaguates (árbol) (T) [(6)Tp.120,(3)xp.38]. This may ultimately be derived from CUAHU(I)-TL ‘tree’ and ZAHUA-TL ‘pox, rash, disease,’ despite the discrepancy in vowel length. T has lost the final labial consonant of the first syllable.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 66.