Plants belonging to the cactus genus Copiapoa are regarded as choice and desirable in cultivation. The most sought after are species such as C cinerea which are slow-growing and take many years before flowering in cultivation. However, the genus includes some miniature species which are easy to grow and flower in our glasshouses. One of the most attractive of these is C hypogaea and its form C barquitensis.

All Copiapoas are native to Chile and inhabit the dry coastal regions of the Atacama desert. The northern part of the distribution area rarely receives rainfall and the plants growing there rely on the heavy fogs which drift inland from above the cold sea. The miniature species of Copiapoa survive this hostile climate by storing water in tuberous roots or swollen underground stems and pulling themselves down level, or even below, the mineral soil. This makes them difficult to find in habitat except in rare years when they receive more moisture.0913 C hypogea Fig1

C hypogaea

C. hypogaea has a small distribution area around the town of Chañaral, including a hill to the south, behind the town of Barquito. Various enthusiasts have found the plant in the wild and introduced it into cultivation, starting with the German Friedrich Ritter who found it in 1954 and described it as a new species in 1960. In cultivation, it makes a cluster of neat heads which have an attractive dark epidermis. The yellow flowers are easily produced and have prominent stamens which look like a starburst. The plant should be given the sunniest location available and watered carefully in warm weather in summer, avoiding stagnant moisture which can rot the roots. A suitable potting soil, which can be left undisturbed until the plant outgrows the pot, should have a high percentage of fine gravel with little organic material. The best results can be obtained by watering with rain water and occasional feeding with a low-nitrate fertiliser.

0913 C hypogea fig2

C hypogaeathis paler skinned version is foten known as Lizard skin. 

The main water-storage part of the species is a fat base or caudex that can reach about 12cm diameter in very old specimens. The top of this has many growing points that produce narrow stems covered with silvery scales; the flowers being terminal on the very ends of these. Unfortunately it is very slow-growing and it takes me about four years to produce a plant from seed that has a 1cm diameter caudex. However, I find it surprising that it will start to flower at about two years old, when the caudex is just a few millimetres across. The species is susceptible to overwatering and I therefore use a very open compost consisting of 1 part each of John Innes compost No.2 and 4mm grit. It should be treated as a summer-grower and watered from March to October. Grow in full sun and keep frost-free and dry during winter.

Graham Charles

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