Syringa vulgaris ultimately for the plants, was Pietro Andrea Mattioli, as one can tell from a unique copy of Tradescant's plant list in his Lambeth garden, an adjunct of his "Musaeum Tradescantianum"; it was printed, though probably not published, in 1634: it lists "Lilac Matthioli". That Tradescant's "lilac of Mattioli's" was a white one is shown by Elias Ashmole's manuscript list, "Trees found in Mrs Tredescants Ground when it came into my possession" (1662): "Syringa alba". In the American colonies, lilacs were introduced in the 18th century. Peter Collinson, F.R.S., wrote to the Pennsylvania gardener and botanist John Bartram, proposing to send
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