I think it's the only cactus that has double coloured flowers that I own. And this year it is much more visible that last year. Also the flowers have much nicer shape.
Damn the flower is gorgeous!
Sulcorebutia Canigueralii
Like most of my cacti, this also is a very small one. And it will stay like that. It may (and I hope it will) grow multiple offshots and with time they will create a nice bunch. But it's still gonna be small.
It is native to Bolivia and likes very fast draining soil. It has a tap root that doesn't like to stay wet too long (it is very easy to rot it). It stores enough water and nutrients for the dry times. In winter, when the temperature drops close to zero degrees C it needs to be kept completely dry. It can withstand freezing temperatures for short periods of time too, though I didn't try that here. We don't get frosts (I keep all the cacti outside all year round).
The flowers... ohhhh boy...
The lighter, almost yellow center and very intensive dark edges look like fire! I don't know what happened that this year the colours seem more intense and more pronounced. I repoted it in spring - maybe the new pot and soil did that.
The body is one of the cutest ones too. When stressed and in summer it turns purple. If grown in more shaded spots it will be darker green. The spines are completely harmless and stay close to the body.
My other blooming cacti:
 Chamaecereus hybrid |  Sulcorebutia Canigueralii |  Mammillaria camptotricha |  Mammillaria Glassii |
 Gymnocalycium baldianum |  Mediolobivia mudanensis |  Lobivia Arachnacantha |  Rebutia hybrid |
 Mammillaria Bombycina |  Mammillaria Gracilis Snowcap |  Mammillaria haageana |  Mammillaria backebergiana |
 Chamaecereus silvestrii |  Mammillaria prolifera |  Rebutia Fabrisii var. Aureiflora |  Lobivia Wrightiana |
 Aylostera Flavistyla FR756 |  Parodia concinna |  Mammillaria Copper King |  Gymnocalycium Bruchii |
 Mammillaria backebergiana |  Gymnocalycium damsii |  Echinopsis subdenudata |  Rhipsalis pilocarpa |
 Mammillaria Prolifera |  Lobivia arachnacantha v. vallegrandensis |  Mediolobivia atrovirens |  Mammillaria magnimamma |
 Sulcorebutia langerii |  Sulcorebutia frankiana |  Chamaelobivia no ID |  Rebutia Albiflora |
 Mediolobivia atrovirens var. ritteri |  Gymnocalycium damsii var. tucavocense |  Notocactus Ottonis |  Gymnocalycium Friedrichii |
 Turbinicarpus Viereckii |  Rebutia neocumingii |  Notocactus Rubrigemmatus |  Lobivia no ID |
 Sulcorebutia albissima |  Lobivia arachnacantha II |  Notocactus mueller-melchersii |  Mammillaria Prolifera |
 Aylostera heliosa var. condorensis |
Shot with Nikon D5500 + Sigma 105mm lens
All photos and text are my own.