Macuilxochitl.

Auh yn tenochtitlan chane ytoca Macuilxochitl tequihua çan mexicatl. auh yn icihuauh ytoca chiMallaxochitl. yehuantin in oquichiuhque. oncā otlacat yn tlacatl. Acamapichtli achto tlahtohuani yehuatl mochiuh yn tenochtitlan. ynin in icihuauh ytoca yllancueytl tetzacatl catca yn cihuapilli amo pilhua. ynin cihuapilli illancueytl yuh mitohua ychpoch xochitonaltzin pilli culhuacan.3 = And a native of Tenochtitlan named Macuilxochitl tequihua, an ordinary Mexica, and his wife, named Chimallaxochitl, begot and thence was born the lord Acamapichtli, who became the first ruler of Tenochtitlan. His wife, named Illancueitl, was barren; the noblewoman was childless. This noblewoman, Illancueitl, so it is said, was a daughter of Xochitonaltzin, a Culhuaque nobleman. (central Mexico, early seventeenth century)
Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Culhuacan, and Other Nahuatl Altepetl in Central Mexico; The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, eds. and transl. Arthur J. O. Anderson and Susan Schroeder (Norman: University of Oklahoma Press, 1997), vol. 2, 82–83.

a solar fertility god (central Mexico, sixteenth century)
Thelma Sullivan, "Tlatoani and tlatocayotl in the Sahagún manuscripts," Estudios de Cultura Nahuatl 14 (1980), 225–238. See esp. p. 231.

This deity was worshipped by people in the palaces. It was required that people refrain from sex when fasting in relation with this deity; if they broke the rule, they were punished with venereal diseases. Making vows and fasting to Macuilxochitl could help alleviate the diseases. His feast was called the Feast of the Flowers, and fasting for this lasted four days. The details of the fasting and the use of flowers are described in the Florentine Codex. (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 1 -- The Gods; No. 14, Part 2, 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, 1950), 13.