Thunbergia alata or “Black Eyed Susan” is a happy fast growing and long flowering vine. It is a favourite here in South Africa, as it is not fussy about the soil and needs only moderate water. It is mostly evergreen and covers ugly places fast.
Black-eyed susan is probably pollinated by bees. An insect visiting the flower will touch the stigma first, with its back, and then the anthers, getting a load of pollen that is then carried to another stigma. The flowers reflect ultra violet light in a pattern that is visible to insects but not to humans. This helps insects find the centre of the flower. Seeds are perhaps ejected mechanically when the fruit splits open. A butterfly, Junonia ovithya, or the eyed pansy, and moths also visit these plants to lay eggs, for the larvae eat the leaves. Hence this creeper, being attractive to insects, helps bring birds into a garden. Birds also often nest in the thickly tangled stems.