Duvernoia adhatodoides E.Mey ex Nees

Family: Acanthaceae
Common Name:
Pistol Bush, Pistoolbos

Duvernoia adhatodoides

Duvernoia adhatodoides is a shrub or a small tree 1-3m in height. It is commonly found on forest understorey, on forest margins and rocky outcrops in the province of Kwa-Zulu Natal and the former Transkei area in the Eastern Cape Province. It is also found in the Gauteng Province. This is an evergreen single or multi-stemmed shrub with dense dark crown. The stems can be as thick as 260mm in diameter with dark brown rough bark. The shiny, dark green leaves make this plant interesting even when it is not in flower. Flowers are conspicuous, an attractive white to mauve with purple markings. This shrub flowers from February to August.

The flowers are pollinated by large black and yellow carpenter bees. Mrs M.E.Barber, a well-known naturalist who lived in the Eastern Cape over a hundred years ago, wrote an article in Journal of the Linnean Society in 1871 describing how the bee alights on the lower lip and forces open the corolla tube with its proboscis to gorge on nectar. In doing so the bee's thorax gets dusted with pollen. It then flies on to another flower where its thorax brushes against the protruding stigma, depositing pollen to ensure fertilization, before picking up a more pollen. The fruits are club-shaped capsules, about 3 x 1 cm, dehiscing explosively with a loud crack (hence the common name).

Growing Duvernoia adhatodoides

D. aconitifloraThis shrub is an excellent decorative garden plant. It can also be used as a background planting in a landscape.

This plant can be grown from seed or cuttings. Duvernoia adhatodoides is sensitive to frost. However, with some protection it can grow in areas where frost is not too severe. Duvernoia adhatodoides is best grown in moist coastal gardens. It thrives in Cape Town and Port Elizabeth. It likes well composted soil as it occurs naturally in forests. Mulch to keep soil water in the soil and to regulate soil temperature. Growth can be stimulated by various fertilizers such as Supa Natural (Fish emulsion fertilizer),Seagro and Kelpack. Seagro and Supa Natural can be used as foliar feed.

Duvernoia adhatodoides is pretty in flower at the Arboretum (the tree section) in Kirstenbosch Garden. Numerous seedlings at the base of the plants are an indication of how easily it germinates. Seedlings are resistant to fungal diseases but a fungicide can be applied when neccessary.

South Africa only has two Duvernoia species. The other species, D. aconitiflora, which also flowers during autumn, is a small shrub to 3m from the north eastern part of South Africa. It is well suited to smaller gardens.

Giles Mbambezeli
March 2001

To find out if SANBI has seed of this or other SA species, please email our seedroom.

This page forms part of the South African National Biodiversity Institute's plant information website www.plantzafrica.com