Aristea, is a genus of plants in the Iridaceae (Iris) family. The fifty five species in the genus are found distributed throughout Africa and Madagascar. Aristea major, synonym A. capitata, is native to South Africa. Its common name is Blue sceptre and it is known as Cetro azul in Spanish.
Although drought hardy, Aristea will benefit from regular watering in the summer and is also suitable for planting at the edge of a pond. It is a big plant, reaching 1.5 metres tall by about one metre wide and spreads by its rhizomous roots to form a dense clump. The long, narrow leaves are evergreen and provide a stunning architectural element whether in a large pot or as an accent plant in the border.
The tall flower spikes are crammed with hundreds of flower buds which open a few at a time with each one lasting just a day. Most common varieties have deep-blue flowers with yellow anthers but there are pink and white varieties available too. The flowers are particularly loved by bees and butterflies and have a subtle fragrance. Once flowering has finished the spent stems can be removed but if left, they turn a reddish brown and add winter interest.
Aristea needs plenty of sun but like most blue flowered plants, the colour of the blooms appears more intense if given a little shade during the hottest part of the day.
Propagating Aristea can be tricky. Not all varieties produce viable seed and if the seed does germinate, the resulting plants may take between three and ten years to flower. Aristea can be divided but dislikes root disturbance and the rhizomes must not be left to dry out. However in ideal conditions it may self-seed.
A smaller version of A. major is A. ecklonii which is said to be much tougher, withstanding both drought and some frost.