Conium maculatum disturbed ground. It is used as a food plant by the larvae of some Lepidoptera species, including silver-ground carpet. The poison hemlock moth ("Agonopterix alstroemeriana") feeds on the plant during its larval stage. "A. alstroemeriana" has been widely used as a biological control agent for "C. maculatum". Poison hemlock flourishes in the spring, when most other forage is gone. All plant parts are poisonous, but once the plant is dried, the poison is greatly reduced, although not gone completely. The plant is poisonous to animals that graze on it. "Conium" contains the piperidine alkaloids coniine, N-methylconiine, conhydrine, pseudoconhydrine and gamma-coniceine
What Is and What Should Never Be and What Should Never Be" was performed live at Led Zeppelin concerts between 1969 and 1973. A live version taken from a performance at the Royal Albert Hall in 1970 can be seen on the "Led Zeppelin DVD". Another was included on disc two of the live triple album "How The West Was Won". Two more versions were included in BBC Sessions. What Is and What Should Never Be "What Is and What Should Never Be" is a song by English rock band Led Zeppelin. It was written by Jimmy Page and Robert Plant and was included as the second