Vanilla imperialis

Vanilla imperialis is an orchid found from Sierra Leone eastward to Ethiopia and southward to Tanzania and Angola. It is a root-climbing vine to about 65 feet in height, with a root emerging just above each leaf. Although not as tall as the common vanilla, it is up to a full inch in thickness; the most massive Vanilla species, and the largest of all African orchids. The inflorescence is an unbranched raceme up to six inches long. The flowers are six inches wide with the white or yellow petals and sepals three inches long by 0.75 inch in width. The labellum is 2.5 inches in length with the far end flared and pink or purple. Most of the labellum is fused to the column, forming a tube. Each flower is open for at least two days.