Plant Common Name
Lapeirousia, Long-tube Iris
This entry has yet to be reviewed and approved by L2G editors.
This genus comprises between 35 and 40 species of herbaceous perennials that grow from bulb-like underground corms. Some taxonomists place species into three or four other closely related genera (such as Ixia), leaving less than 20 species still in Lapeirousia. The species are most concentrated in southwestern sub-Saharan Africa, but Lapeirousia exists from Nigeria to Ethiopia southward to the tip of the continent. They are particularly unique in that they are more widespread in more arid parts of Africa, rather than concentrated in the moister regions of South Africa or the Great Rift Valley. These plants naturally die back each year, with a dormancy during the prolonged dry season drought. Collectively, they may all be colloquially referred to as the long-tube irises.
The iris-like leaves emerge from the bell-shaped corms when temperatures are warm and seasonal moisture returns. Depending on species, only one green lance-shaped leaf exist, or there may be several in a fan-like plane. Leaf blades are either flat or curved, smooth or pleated. Flowering occurs after leaf emergence, varying by climate and elevation. For example, in more equatorial parts of Africa, the species bloom during the spring to fall rainy seasons. However in South Africa, where a Mediterranean climate dominates, flowering occurs anytime from mid-autumn to late spring, when the annual rains occur or have made the soil moist. Flower colors range from white, pink, red, blue-violet or purple. The blossoms are held in tufts or clusters on stems that arise directly from the underground corm. In a few species, the flower stalk branches. Insects pollinate the tube-shaped flowers, ranging from long-tongued bees and flies to various moths and butterflies. The shape of the flower and length of the flower tubes can be very specific for pollinator species. Lapeirousia fruits are capsules.
Lapeirousia plants may be simply described as diminutive, grass-like plants with very striking, beautiful flowers. They are best grown in sunny conditions in a well-drained, organic, porous soil ranging from sand to gritty loam. They are not especially cold hardy, and in temperate regions, Lapeirousia are best grown in containers and shielded from subfreezing temperatures indoors, even when plants are dormant. Water and fertilize these perennials from spring to fall but reduce watering and halt fertilization heading into winter to force the needed dormancy. Some ornamental species are known to remain dormant for multiple years. It's best to err on the side of waiting and not digging up corms. Plants tend to respond poorly to overambitious dividing and root disturbance.