Catalpa produces large, white flowers with conspicuous red-yellow nectar guides along the lower petals. The nectar guides change from bright yellow to a reddish-orange on older flowers even though the petals remain looking fresh the long, cigar-shaped fruit is filled with small, membrane-winged seeds. Catalpa’s heart-shaped leaves are arranged in a whorled pattern. The leaves are large and heart-shaped. Extra floral occur between the main veins underneath the leaves. The champion New York tree is 77 feet tall with a circumference of 205 inches in Oneida County. The national champion is 81 feet tall with a circumference of 285 inches in Indiana.