Apium virus Y Apium virus Y "Apium virus Y" (ApVY) is a plant pathogenic virus in the genus "Potyvirus" and the virus family "Potyviridae". Apium virus Y is a recently described member of the potyvirus family. It was first found in Australia in 2002 in poison hemlock ("Conium maculatum": an immigrant weed in Australia). A survey of native and weed species in the family Apiaceae found ApVY to be widespread in Australia. In addition, this survey and others found two other potyviruses. One was a well-known potyvirus infecting the Apiaceae, "Celery mosaic virus" (CeMV). CeMV has been found in celery ("Apium graveolens") crops
What Is and What Should Never Be descending riff [of "What Is and What Should Never Be"] is amazing: It's like a bow is being drawn back, and then it releases. The rhythm of the vocals is almost like a rap. It's insane — one of their most psychedelic songs." This was also one of the first songs recorded by the band for which Robert Plant received writing credit. According to rock journalist Stephen Davis, the author of the Led Zeppelin biography "Hammer of the Gods: The Led Zeppelin Saga", the lyrics for this song reflect a romance Plant had with his wife's younger sister. "What Is