Instead of spines it has numerous white or yellow glochids 2–3 mm long in dense clusters.

They are barbed and thinner than the finest human hairs, detaching in large numbers upon the slightest touch.

If not removed they will cause considerable skin irritation so the plants must be treated with caution.

Despite this, it is a very popular cactus in cultivation, partly because of the young plant's comical resemblance to a rabbit's head.

[6] One reason for the success of O. microdasys in desert habitats - at home and as an introduction - is its efficient fog collection ability.