Houseplant botany 4

29th December 2021

Some cacti have spines in sheep's clothing - they develop a covering of dense hairs so that the cactus itself appears almost woolly. These hairs protect the plant from frost and sun by insulating the stem and reflecting back strong sunlight, but only some of the outer spines are modified into hairs: sharp yellow central spines are hidden underneath them. If you grow Cephalocereus senilis, place it in the brightest possible position, to encourage plenty of hair growth.