All you wanted to know about Haworthias, Gasterias and Astrolobas: Astroloba rubriflora

Astroloba rubriflora, near McGregor

Astroloba rubriflora

(L.Bolus) Gideon F.Sm. & J.C.Manning

by Jakub Jilemicky and Steven Molteno

rubriflora: red flowered

This large, robust, distinctive plant has long been classed in its own separate genus, as Poellnitzia rubriflora, on account of its unique red flowers. Now moved to genus Astroloba, it is nonetheless clearly an outlier within this genus. Its sharply-pointed leaves are usually smooth and assume a blue colour when protected from direct sunlight.

Typical Astroloba rubriflora flower

Astroloba rubriflora, W of Bonnievale

Its attractive red flowers appear in summer (December to April), standing upright, along the horizontal tip of its inflorescence.

This species is endemic to the Robertson Karoo vegetation of the Breede River Valley. Here it is usually found under bushes and on rocky slopes, outcrops or koppies. Its centre of distribution is between Robertson, Bonnievale and McGregor. Outlying populations to the west near Dublin farm are dwarfed and gracile, and also highly variable in form, some even bearing tubercles. Another outlying population supposedly occurring to the north-west near Worcester has splayed, recurved leaves and is sometimes classed as the variety jacobseniana (Poelln. 1937).

Distribution map

Astroloba rubriflora is relatively easy in cultivation, provided that its dry, winter-rainfall climate is replicated somewhat. Its natural soils are clay shales, but it tolerates most well-drained mixes. It assumes an attractive blue colour in the shade. It can be propagated by seed, or by cuttings/offsets which should be dried for several weeks in a cool shady spot before being planted.