See an image that represents popoyotl in the Visual Lexicon of Aztec Hieroglyphs, ed. Stephanie Wood (Eugene, Ore.: Wired Humanities, 2020-present).
In Book 6 of the Florentine Codex we see Anderson and Dibble have translated popoyotl (popoiotzintli) as more than a small bit of rottenness or decay, but as an ear of "smutty maize." In this context, the reference is to a newborn child. (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), chapter 33, 181.
cujx popoiotzintli in njcan tictomaviҫalvilia totecujo = perhaps here [with an] ear of smutty maize we bring honor to our lord (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 181.