The wild foxglove varies in height, depending on the amount of water it receives during the summer. In the garden, with regular watering, they grow 1.5-2 m tall. Some plants become quite bushy while others remain single-stemmed. The soft, green leaves are about 50 mm long, divided into 3 lobes, with a bluntly serrated margin. The leaves are carried on long thin stalks up the stems. Plants with pink flowers usually have dark red stems while the white-flowering form have yellow-green stems. The leaves, stems and flowers are covered in fine white hairs. The plants are slightly sticky and when crushed give off a strong unpleasant smell. The flowers last for a few days in the vase.

The beautiful white or mauve foxglove-like flowers are carried in pairs up the stems in tall, sparsely flowered spikes. Unfortunately the promise of an overwhelming display is never fulfilled as only two or three flowers on a stem open at a time. The bottom flowers open first and form fruits while new buds are still developing at the tip of the stem. Each flower is about 50 mm long with 5 lobes, the bottom lobe longer than the others and streaked with delicate lines running into the throat.

In nature the wild foxglove flowers throughout summer but at Kirstenbosch the best display is during the late summer months (Feb.-Mar.). The small black seeds are formed in the 30 mm long fruits which have two very prominent horns at their tips. Within a few weeks of flowering, the green fruits dry and turn brown, splitting open to release the flat, pear-shaped seeds.