Sulphur-flowered prickly pear
[NB This species was previously incorrectly listed in the Atlasing system as Opuntia phaeacantha]
Origin: South America
Low-growing, dense thicket-forming, spreading, very spiny, succulent shrub usually up to 1 m high, often shorter. Cladodes (flattened stem segments) green to dark green (sometimes flushed reddish when water stressed), ovate, up to 25 cm long, 20 cm wide and 1-2 cm thick. Areoles (spots on cladodes and fruits that carry the spines and glochids) usually bearing 2-8 robust spines 1.5-5 cm long and many glochids (short, fine, barbed bristles) that may be concentrated in a semi-circle at the areole base. Spines often spreading or flexed downwards, characteristically red-brown when young, especially at edges of cladodes, becoming grey to whitish with age. Flowers delicate, rose-like, light to bright yellow, often with pink or reddish markings on the outer 'petals' up to 7.5 cm across. Fruit fleshy, ovoid with flattened tip, without distinct, narrowed ‘neck’ at base, up to 6cm long, with scattered tufts of glochids, green at first, bright pink to waxy magenta when ripe; flesh green to reddish, with many yellow-brown seeds.
This is a highly invasive species that has rapidly and aggressively occupied considerable parts of the Windhoek townlands. At present we have no known biocontrol agents for it. It has the potential to become a very serious threat to indigenous plants and animals, including domestic stock.