The cauliflower in the Twenty-Four Flowers Trade Wind refers to rapeseed flowers.
Twenty-four flowers bloom in the rainy season when the trade winds and rains come. That is, the cauliflower blooms during the rainy season, and the rain begins on February 18th or 19th and ends on March 4th or 5th. It's the season when rapeseed flowers are in full bloom. In addition, the flowers in the trade wind are representative plants of the season and are relatively common. Rapeseed flowers fit the bill in terms of flowering date and frequency.