It lists Asparagus Fern as one of the common names. Probably one of those, someone said it and the rest of us ran with it things because I do know of the Asparagus Fern Anna mentions, but I kind of use "Asparagus Fern" interchangeably with "Foxtail Fern." And I call the other one "Asparagus Fern."
And they are both of the same genus as Asparagus, so I think saying "Asparagus Fern" is kind of a catch all for the "ferns" in the genus.