IN THE GARDEN
From page 31 conditions . All parts of the plant are poisonous when ingested , and handling the plants may irritate or even blister the skin . Small infestations can be removed mechanically , but all seed pods should first be removed to prevent recolonisation , and gloves should be worn to protect the skin . Once the plants have been removed , ensure that the entire rhizome has also been removed be-cause any remnants will merely regrow . Removed plants can be burnt or allowed to rot in black bags in the sun to prevent them from re-growing where they are discarded . Smallholders are urged not to plant this species but rather to grow the indigenous yellow vlei iris , Moraea huttoni , which also produces attractive , yellow flowers , and can be used in similar situations . Another ornamental alien that has escaped cultivation to become invasive in many parts of the country is the Madagascar Periwinkle ( Catharanthus roseus ), a declared invader in South Africa which must be controlled , or eradicated where possible . It is an erect , perennial plant up to one metre high , with a
Butterfly Bush
Madagascar Periwinkle
woody base . The leaves are bright green and glossy , with attractive pink or white flowers in the axils . Each flower has five petals that fuse to form a tube at the base . Plants flower throughout the year . Infestations can be removed by hand-pulling . Gloves should be worn to protect the skin from the latex , and all seeds must first be removed from the plants to prevent them from germinating in the disturbed soil . The collected seeds must be destroyed , preferably by burning . Herbicides designed for broad-leafed plants may be used . The third member of this terrible trio is the Butterfly Bush ( Oenothera lindheimeri), which is a perennial herbaceous plant native to parts of North America , which was imported into South Africa as a garden ornamental . It grows upright and spreads in a grass-like manner from a woody root-stock , and can reach as high as one metre . Attractive , butterfly-shaped flowers are borne in spikes , and open at sunrise in sequence along long stems . Owing to the fact that
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