Mammillaria plumosa is native to Nuevo Leon, Mexico and is commonly known as "Feather Cactus" because of the feathery spines. Most Mammillarias are native to Mexico but they can be found from the southwestern US all the way south to northern parts of South America.
The cute and cuddly appearance of the Feather Cactus is a bit deceiving as I learned earlier when I was repotting this one-it has some real sharp spines below the innocent looking surface. The colors of the flower for this cactus vary from white to pink and are more striking than the flowers on my plant. The feathery spines of this cactus are also usually a very pure white color but they are prone to staining from watering from above or becoming dusty. When I first received this cactus it fell over and got covered with dirt and the feathery spines have looked dirty since then. The growth of the spines is not just attractive but it serves a purpose, they've adapted to grow out in this manner to provide shade for the plant.
Mine has survived in spite of (or maybe because of) my benign neglect in growing this plant. This spring and summer it lived outdoors in full sun and only got water only when it rained. Had I taken charge of the watering I probably would have killed it since Mammillaria plumosa is a rot prone species when it gets too much water. Because of this a good fast draining cacti and succulent soil mix is needed to grow this plant.
I'm not a big fan of spiny cacti and the only real reason I have this plant in my collection is because it was given to me by a friend and because of the feather-like spines that make it a plant people want to touch or talk about.
Feather Cactus has a clumping growth habit so if you'd like to propagate yours you can do it by removing some of the offsets-it can also be propagated by seeds.
How I repot a cactus
How to repot a cactus (part 2)