👉 Pterygostemon is a type of flowering plant in the family Apiaceae, commonly known as the butterfly pea or buttercup bean. It has a long, slender stem with narrow leaves that are flat and glabrous (not covered by hairs). The flowers are arranged in clusters at the ends of the stems, often forming a cluster around the base of the flower. Pterygostemon is native to many regions across Central and South America, including Brazil, Argentina, Paraguay