Neochilenia jussieui
Native range: Chile
Known names: Eriosyce heinrichiana
Hardiness: Can take down to 32°F if kept dry in winter.
Mature Size: Grows slowly to ~6" inches tall.
Light: Direct sun, Half day sun- avoid hot afternoon sun. 
Water: Water during summer (let soil dry out completely), keep dry during winter.
Soil: Cactus/Succulent mix
Dormancy Period: Winter
Pet-Safe: No
Plant Size: Grown in 2" pot, shipped semi bare root
 
*Different plant can show various levels of purple*
Dark sage green ranging to dark purple. Black/maroon/grey spines!!! This one is for you, goth plant lovers!
Fairly easy to grow but will require some attention during mid summer to make sure that your plant doesn't get sunburnd. Other than that, grow it like your typical South American cactus...so no summer monsoon flushing, just water once in a while.