Love those Gymnos, (can one have to many, but what is to many?).........I purchased this G. mostii from Kara Nursery at the Oregon Cactus and Succulent Society Sale at Portland Nursery on Stark St. in July. This plant is about 6+" wide and about the same height. And of course it had the bud when I purchase it, one of the reason it was added to the collection. It is usually a weakness when a Gymno is setting flower buds. I have not had the chance to see the flower open, since I'm at work during the day. Maybe I'll get to see it tomorrow if the flower is still in good shape.
The flower color is listed as pink, but to me its a little more on the apricot side. G. mostii is from the area of Córdoba in Argentina where it grows among grasses in the mossy cracks and cavities in rocky cliffs. The plants in habitat are different from its neighbors. Some have strong spines others weak, curly, straight, long or short ones and in all different combinations.
They have been described as solitary, but they can also form groups with age. It is a summer grower species that offers no cultivation difficulties. Water regularly in summer and keep this plant almost dry in winter at a minimum temperature of 32 degrees.
After looking thru my many books and viewing websites,I believe this to be a Gymnocalycium achirasense var. orientale. I'm very sure I'm correct, but I would not bet the greenhouse on it. As always the flowers are amazing.........I moved this plant from Death Valley Shack to the kitchen table to enjoy the flowers!
Gymnocalyciums in habitat are found in South-Eastern South America in various environments and elevations.
The Gymno. achirasense grows in Argentina in the foothills of the city of Cordoba. The variety name "orientale" means that it lies in the most eastern part of the habitat. Achirasense is a (usually) solitary cactus, flattened or globular, dark-green, grey-green to olive green, 2"-3" in diameter up to 2" in height, but in cultivation it can become 4" high (or more) over the years. 10-12 spines which are stout and aggressive, but usually fewer in young plants, bent against the body with a rib count of 12-15. Central spines are usually absent or they have 1 erect. The flowers are some of the largest in this genus, often growing larger than the plant, whitish, pale pink to lavender, with a darker mid-strip.The cultivation of this plant as well as other Gymnocalyciums is simple. They are summer growers, water regularly in summer, keep rather dry in winter. They will flourish in full sun (not direct) or light shade. The Gymnocalyciums are one of the easiest of the cacti to grow, to have flower and can flower at an early age.
The flower color is listed as pink, but to me its a little more on the apricot side. G. mostii is from the area of Córdoba in Argentina where it grows among grasses in the mossy cracks and cavities in rocky cliffs. The plants in habitat are different from its neighbors. Some have strong spines others weak, curly, straight, long or short ones and in all different combinations. 
They have been described as solitary, but they can also form groups with age. It is a summer grower species that offers no cultivation difficulties. Water regularly in summer and keep this plant almost dry in winter at a minimum temperature of 32 degrees.
