All three of the commonly-recognized species of Calycanthus (sweetshrubs or spicebushes) have previously been featured on BPotD: Calycanthus occidentalis from western USA, Calycanthus chinensis from eastern China (syn. Sinocalycanthus chinensis), and Calycanthus floridus from eastern USA. A fourth species, Calycanthus brockianus, endemic to Georgia (USA) is sometimes accepted.
Calycanthus floridus ‘Athens’ is a yellow-flowered variant of the species. Prominent horticulturist Michael Dirr makes note of the history of this taxon in his Manual of Woody Landscape Plants, stating that the origin of the yellow-flowered variant has been “lost to antiquity”. He further describes it as having a “tremendous fragrance–as good as I have ever experienced on any sweetshrub…this plant has brought great delight to our garden and home and virtually every garden could make use of such a plant”. This cultivar was introduced to the trade through the plant evaluation programs at the University of Georgia in Athens (the photo is from the State Botanical Garden of Georgia, also in the city).