Hyacinthus was a young love of the Greek God Apollo. Apollo accidentally killed him, and from his blood sprang the hyacinth, a plant with a fragrant cluster of flowers.
The line, "I see the bathroom is clear" could refer to the bathroom in the studio where the song "L.A. Woman" was recorded. At the time, Jim Morrison insisted on recording the vocal track remotely from the bathroom rather than in the studio with the rest of the band. (thanks, Sam - Lincoln, NE)
The song was written at guitarist Robby Krieger's house, which inspired some of Morrison's lyrics with its flowers (hyacinths) and cats ("lions").
According to Uncut magazine September 2011 the line, "I see the bathroom is clear," was literal. Morrison's friend Babe Hill emerged from the bathroom just as he was writing that verse.
