African Wildlife & Environment Issue 82

GARDENING FOR BIODIVERSITY

The only other indigenous species of Plumbago is the Wild White Plumbago P. zeylanica , which is very similar to P. auriculata but has pure white flowers. Its natural distribution area stretches in a westerly direction from KwaZulu-Natal to the Northern Cape and North West Province. This also extends beyond our borders into Namibia, tropical Africa and several other countries of the world. Despite being so cosmopolitan, it doesn’t occur as far south as the Western Cape. Where natural areas are still left in Gauteng, it is often found growing in shady places on wooded hillsides. This species makes an ideal garden plant, but is not commercially available as readily as is a cultivar

Although mostly evergreen, the plant does sometimes lose quite a number of leaves during very cold winters. The oblong or wedge-shaped leaves are held on stalks, which are characteristically winged at the base, partly clasping the stem. Reference is made to this feature in the species name auriculata , which means ear-shaped and which has replaced the old name capensis .The genus name Plumbago comes from the Latin word ‘plumbum’ which means lead. The word ‘plumber’ shares this origin as in days gone by water pipes were made from lead. Because plants of the genus Plumbago were supposed to be a cure for lead poisoning, the association with lead remains. In fact, a frequently used alternative common name for P.

The flowers of Plumbago auriculata are insect magnets attracting, for example, the butterfly seen at the bottom of the photo (Photograph: P Vos)

auriculata is the Cape Leadwort. Although less likely, it may also be that the name derives from the lead blue colour of the flowers. Widespread, P. auriculata is found naturally throughout the northern provinces, including Gauteng, down to the Free Sate, KwaZulu-Natal and the Eastern Cape. In the Western Cape, it doesn’t reach much further south west than George without human help. However, in the Karoo area of that province, on dry sandy slopes up to an altitude of about 1 000 meters, a relatively unknown species Plumbago tristis , which has dark orange-red flowers, is endemic (occurs nowhere else in the world).

of P. auriculata that also has white flowers. Several varieties of P. auriculata with darker shades of blue flowers have been cultivated and are freely available at nurseries. Mainly occurring naturally in warmer regions, the ten or so Plumbago species worldwide include two found in Namibia. That brings the count for southern Africa to five, about half of all the known species! Although P. auriculata is most easily propagated by lifting suckers, it will also grow from cuttings and seed. Offspring frequently come up in the vicinity of the plant, and these seedlings are ideal for transplanting when still small. The seeds are held in grooved capsules, the tops of which split open like

37 | African Wildlife & Environment | Issue 82 (2022)