Night-flowering cactus

Description:

Substantial tall, longitudinally ridged, green stems (to 4+m), sparsely branching above but can form a dense clump with many close stems from ground level, leaves reduced to spines. Large white flowers flowers open at night (to 25cm long and 15cm wide) composed of numerous floral parts (primitive floral structure); flowers fading as the sun strikes them. Fruit a pink barrel shaped "prickly pear" about 6-8cm long with white flesh and numerous tiny black seeds.

Habitat:

this is an exotic garden escape which has naturalised in the south and east of Botswana. It grows among the bushes and small trees of the bushveld, often protruding beyond the surrounding canopy. The climate is relatively hot (touching 40C in the summer), experiencing erratic summer rainfall (450-500mm) and dry winters with daytime temperatures to about16C and occasionally falling to below zero at night

Notes:

this species is considered a problem alien in moister parts of the south east region where it has managed to gain a strong foothold, in other areas of Botswana it does not thrive to the same extent. These photo were taken in a farm garden on a (rare) overcast and foggy morning hence the dew and the fact they were still in good condition in daylight