This image of a tulip was made as part of a tulip book used as a grower’s marketing tool during the so-called tulip mania. a speculative bubble in 17th-century Holland. when ten tulip bulbs could cost more than a stately Amsterdam canal house. The striations on the tulip. which were caused by a virus in the bulb. made it especially valuable. Pieter Holsteyn II was one of many artists in the Netherlands at the time who specialized in botanical illustration. Nancy F. and Joseph P. Keithley Collection Gift