Macrogonus - Trichocereus macrogonus

Macrogonus: a cutting of Trichocereus macrogonus

Trichocereus macrogonus, also described as Echinopsis macrogona, is a columnar cactus from South America. In the wild it grows into a plant of roughly 2.5 to 5 metres with branches about 6 to 15 centimetres thick. What stands out are the ribs: usually six to eight of them, thick and strongly rounded, with a transverse groove in the skin above every areole. That skin carries a bluish green bloom. The areoles themselves are round, grey to dark brown and sit more than two and a half centimetres apart. Older areoles can carry up to twenty spines, including three or four longer central ones that reach some five centimetres. At night the plant opens large, pale flowers that can measure over twenty centimetres in total length, though only on well-grown specimens.

The species was described in 1850 by Salm-Dyck as Cereus macrogonus; the name comes from the Greek makros (large) and gonia (angle) and refers to those broad ribs. In 1974 Friedrich and Rowley placed it in the genus Echinopsis. Current classification also puts the San Pedro here, as Trichocereus macrogonus var. pachanoi, recognisable by its much shorter and thinner spines. In South America various Trichocereus species have long been counted among the sacred cacti. What you buy here is a cut piece of column without roots, so your specimen will always differ from the photo.

Rooting the cutting

1. Let the cut surface dry for one to three weeks in a warm, airy spot out of full sun, until it feels hard and closed.
2. Then stand the cutting shallowly upright in a dry, mineral cactus mix with coarse sand, perlite or pumice.
3. Give no water for the first few weeks; roots form precisely in dry substrate.
4. After that, water about every ten to fourteen days during the growing season, and only once the pot has dried out completely.
5. Keep the plant cooler and drier in winter and give it as much light as you can all year round.

More cacti at Avalon

The same category at Avalon Magic Plants holds the San Pedro, the Peruvian Torch, the Bolivian Torch, the Cuzco and the knobbly monstrose forms, both as cuttings and rooted in pots, plus seeds of several Trichocereus species. All plants are shipped discreetly packed.