What was Georgia O'Keeffe's first major oil painting of a flower, completed in 1924?

Georgia O'Keeffe's first major oil painting of a flower was Petunia, No. 2, completed in 1924.

O'Keeffe painted Petunia, No. 2 in 1924, enlarging the flower so that its form fills much of the canvas. The work is important because it marks the beginning of her sustained series of large-scale flower paintings, which became among her most recognizable works. She had made flower-related images before, but this painting is commonly identified as the first of her major flower oils.

Her flower paintings were often interpreted as symbolic or erotic, but O'Keeffe repeatedly rejected the idea that viewers needed to find a hidden sexual meaning in them. She emphasized looking closely at natural forms. Petunia, No. 2 is also easy to confuse with Black Iris III or Jimson Weed, which are later and more famous examples from the same broad subject area.