Gymnos from A to Z

Gymnocalycium chacoense Amerhauser

The mesa Cerro San Miguel is a tectonic upheaval.* Its steep faces are up to 100 metres tall and consist of reddish quartzite. The lower part of the mountain is densely overgrown. G. chacoense can be found on steep rock faces in small crevices or cavities, that are filled with sediments of humus. The plants sprout abundantly. Due to the probably almost exclusively vegetative propagation, there's a large uniformity among the populations in the habitat. During my visit of the Cerro Miguel in September of 2006, the vegetation on the southern part of the mountain was heavily damaged as a result of a fire.
* Putzer: "Geologie von Paraguay" (Geology of Paraguay), publ. by Gebrüder Borneträger, Berlin 1962