How the lemon was invented (2018)
Citrus taxonomy is fascinating.  Of all the citrus that we have, there are only three "natural" plants: the mandarin, pomelo and citron.  Everything else is some cross between these:  <a href="https://en.wikipedia.org/wiki/Citrus_taxonomy" rel="nofollow">https://en.wikipedia.org/wiki/Citrus_taxonomy</a>, in particular, this graphic: <a href="https://en.wikipedia.org/wiki/Citrus_taxonomy#/media/File:Citrus_tern_cb_simplified_1.svg" rel="nofollow">https://en.wikipedia.org/wiki/Citrus_taxonomy#/media/File:Ci...</a>