Georgia O'Keeffe used oil on canvas for the 1932 painting Jimson Weed/White Flower No. 1.
The painting presents a single large white jimson weed flower against a pale background. O'Keeffe enlarged flowers so that viewers had to confront their structures at an unfamiliar scale. She explained that people often did not take time to look closely at flowers, and magnification could make them noticeable.
Jimson Weed/White Flower No. 1 became one of O'Keeffe's best-known works. It sold at auction in 2014 for 44.4 million dollars, setting a record at the time for a work by a female artist. The record was later surpassed, but the sale demonstrated the painting's exceptional market status.
The title is sometimes shortened to Jimson Weed, but the full title identifies the work as White Flower No. 1. Its medium is oil on canvas, not watercolor or pastel.