Citron
A source of confusion is that "citron" or similar words in French (and other languages), and English are false friends, as they refer to the lemon. Indeed, into the 16th century, the English name "citron" included the lemon and perhaps the lime as well.
Greek citron
"This tree does not become particularly big. The leaves are smaller than those of other citrons, and serrated, oblong, pointed towards the front, mixed with many thorns. The bloom is small and reddish from outside. The fruit blossoms (- "the carpels") are not less oblong from the beginning, appearing as reddish and dark-green; thereafter they turn entirely green, and when they ripen, straw-yellow, remaining, however, rather small all the time and never growing to a proper size, like other kinds of Citron.