Thunbergia
We have 4 species here, but one of them, Thunbergia erecta, is a straggly bush that is better grown as a bush and so not included here.
1. Thunbergia alata (Black-eyed Suzy). A small annual that is grown from seed. It will not normally survive the summer. However, the seeds are fairly easy to grow, providing you do not plant them too earlier (e.g. from mid-October). Since it is only about 1 m high, it can either be grown upwards e.g. on a tripod of poles, or allowed to trail downwards. It produces a good display of flowers during the winter months. Although the native colour is deep yellow with a black center, it varies from white, cream, yellow, orange, and with and without the black center (as in photo). It is very prone to attack by spider mite and often mealybugs.
2. Thunbergia fragrans. Despite its name, the flowers are not scented! It is a poorer climber than T. alata and I normally have it trailing from a pot. It has more pointed leaves and has larger more angular white flowers than T.alata. It is much more hardy and will survive the summer in the shade, but will flower better during the winter, if it is in the sun. It is grown from seed and is easy to grow. It may be attacked by mealybugs, but much more resistant than T. alata.
3. Thunbergia grandiflora is a big creeper with big pale blue flowers (but there is also a white variety). It is not hardy (I have only been able to grow it as an annual). Its disadvantages are: the seeds are difficult to germinate; as an annual, it takes a long time to start flowering; the flowers only last a day and it does not flower very prolifically. Maybe, like Mandevilla, it could be kept trimmed back in a small pot that could be moved in to deep shade or even indoors during the summer, otherwise I have given it up, although it is very spectacular when it does flower.