Spikes of blue stars.

Aristea species


Family: Iridaceae

Common names: Blue stars, blousterre

Derived from Latin word arista, meaning ‘spike’ or ‘point ‘and refers to the rigid points of the leaves.

There are 32 species occurring in the Western Cape,  and some can be found  all the way up to Senegal and Ethiopia. Species are most frequent in moist highlands, in grasslands, on rocky outcrops or in marshes.  They are pollinated by monkey beetles as well as bees foraging for pollen. One species, A.spiralis, produces nectar and is pollinated by long-proboscid  flies.  In nature they germinate after fire, and plants flowers profusely the year after the fire. The seeds are dispersed by wind and water.

Aristeas are barely known in cultivation, despite their handsome blue flowers and,  in many cases, elegant foliage.  The reason  is probably  that they don’t transplant well, or that it takes about 3 years for plants to reach flowering size,  which makes them not economical  for growers. Another reason may be the fact that the flowers last only one day;  they open early in the morning, and fade in the early afternoon. However,  there is a succession of flowers up the flower stalk, with the lower flowers opening first, slowly working  up to the apex.

Despite these short-comings, these starry blue flowers  create a soft mist of blue in a semi-shade position, or in a sunny  but not hot area in the garden.  A. capitata  appeared in nurseries last year and is worth cultivating.  These plants are sturdy and have dense clusters of large, deep blue flowers. Each plant produces hundreds of blooms throughout its 4 to 6 week flowering season. The  foliage is handsome and makes a statement in any flower border.

This year Aristeas  have been particularly prolific. Travelling on the Brenton road, passing Belvidere, the road side on the right is covered in profusion of A. ecklonii.  In the Gouna forest you will find A. ecklonii and Dietes iridioides  growing amongst ferns flanking the gravel road;  they light up the scene with a mix of bright blue and white, all very beautiful.   On the Outeniqua mountains  A. capitata  graces the folding landscape of the mountains.  Near the Knysna Elephant Park, in a marshy area,  A. Schizolaena’s bright blue spikes tower over the lower vegetation, and  at Westford Bridge the tiny A. pusilla provides a splash of blue along the pathways.  Aristea ensifolia appeared in  my garden a few years back, and this year for the first time I’m rewarded with lovely spikes of blue ‘stars’.




Contributor: Esther

Photos: Esther