For the identification of insects and other fauna and flora of South Africa.
Wednesday, August 7, 2013
Pistol Bush (Duvernoia adhatodoides)
Family Acanthaceae
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).
