The so-called ’rosulate’ violas are a group of perennial Viola species in which the leaves form a tight rosette, rather like some of the saxifrages. However, the flowers appear at leaf level in rings around the outside of the rosette. They are mainly found in the higher Andes, in Chile and Argentina and grow in relatively bare loose soils, which are often volcanic in origin. Like many plants in such countries they have a long tap root to ensure access to water.
Personally, I have only seen one species and that was Viola auricolor (above) in Southern Patagonia at the extreme south of Argentina. This is the only species in the south but central Chile and Argentina have more species including the beautiful orange-yellow V. coronifera (left) and the white-flowered V. sacculus (below).
They are difficult to cultivate and must be grown from seeds, but magnificent plants of Viola dasyphylla appear regularly on the show bench. (AGS Bulletin Vol. 64 No1 Pg 76).