Pachypodium namaquanum,the halfmens (half plant, half human), is a succulent plant that can attain a tree-like appearance when fully grown. The stem height may range between 1.5 and 2.5 m, although 4 and 5 m specimens have been observed. The stems are mostly unbranched and cylindrical but may become branched from near the base and occasionally have a few shorter branches near the apex (tip). Plants are characteristically thickset at their bases, tapering toward the apex, which gives them an unmistakable bottle-like appearance when mature. The stems are covered with warty tubercles (knob-like projections), from which spines protrude in a slightly downward direction. The spines are more abundant along the top half of the plant and decrease towards the base where tubercles are more prominent.
The leaves, which are borne in rosettes (cluster of densely spirally arranged leaves arising from a central point), are simple, obovate to oblong, green-grey, and densely velvety on both surfaces. Leaf apexes are tapering or rounded, and the bases narrowly tapering. The leaf margins are entire and very wavy which is another distinctive characteristic of this succulent. Leaves are always formed in crowded rosettes near the stem apex.
achypodium namaquanumgrows easily from seed as long as the seeds are fresh and without signs of parasitism. The silky-haired parachutes are removed prior to sowing. Seeds can be sown in the summer using a mixture of river sand and sifted compost or bark at a ratio of 1:1. After germination, care should be taken not to overwater as this encourages rot and fungal infestations. Keep plants well ventilated and in good light, and dry plants out in the dormant season which is summer (October to March).
Pachypodium namaquanumcan also be grown from cuttings, although success is not guaranteed. Cuttings also take an extremely long time to show active growth. They should be taken in the period just before the growing season starts. The apex (tip of the shoot or leaf) of the stem which contains actively dividing cells is used and the wound is treated with a fungicide or flowers of sulphur and then left to dry for at least two weeks. Cuttings are inserted vertically into a well-drained, sandy medium. The same medium used for germinating seeds can be used for cuttings. Cuttings are kept in a hot, well-lit and ventilated area, and watered sparingly in the winter months; once a week should be more than enough.
Plants in cultivation at the Karoo Desert National Botanic Garden and the Kirstenbosch succulent collection seem to benefit greatly from organically derived fertilisers. Plants in the succulent collection at Kirstenbosch are provided with additional heat by means of heat cables that are buried in the soil. It is inevitable that these plants would require this essential heating in the northern hemisphere countries and be sheltered from the colder wet weather.