Hi, I think I just bought a mammillaria cactus. What is the subspecies and how do I care for it best? What colour flowers to expect? What should I do with the fruits sticking out (propagation instructions)? Will the plant's spikes change over time (e.g. Will it grow central spikes, change colour, etc.)?
Thank you.
It might be Mammillaria lasiacantha subs. magallanii. They originate from Mexico, and are slow growers. Put them in well drained soil, and water them only when soil feels dry again. They prefer bright light (direct sunlight), and can't handle frost too much. Detailed care instructions are in the link.
Sorry I skipped right over your other questions. If it's M. baumii it will have yellow, very light citrus-scented flowers. Generally in the spring, sometimes in the fall (fewer flowers).
You can sow the seeds, I have had good luck with Dolichotheles.
It's a pretty standard cactus, care-wise. Give it as much sun as you can, water it when it's dry, feed it occasionally.
Depending on where you live (I'm in Arizona) keep it away from frost in the winter. They go somewhat dormant in the winter, but given enough sun and warmth it will grow slowly in the winter. During the warm months it grows fairly quickly if you keep it watered. If the tubercles get wrinkled it's past time to water.
As a matter of personal style I put small gravel on the soil (top dressing) to keep moisture in. And I generally plant them higher in the pot, meaning where the body and roots meet should be within half an inch of the rim of the pot. Again, not required, but I like them that way.
Another tip, if you live somewhere cold and wet you may consider putting it in an unglazed terra cotta pot. This helps it shed moisture. These soft-bodied Mammillaria are more prone to rotting than other species.
I can say for certain that this is NOT M. lasiascantha. I have owned many in the past and this isn't one. M. lasiascantha is very compact and it is difficult to see any green through the spines. The pectinate spines are similar, but not nearly dense enough. Here are pictures of M. magallanii. It's been elevated to species rather than a subspecies or variant of M. lasiascantha. (depending on who you listen to)
Probably a M. baumii or related (M. spherica). If it has a yellow flower it is probably M. baumii or one of the other Dolichothele species. If not, let us know. Here are some pictures of M. baumii.
Besides the spines your plant has rounded, flabby tubercles which is a key feature of the Dolichothele group. (M. longimamma, M. spherica, etc)
M. lasiascantha is somewhat rare in collections, you won't find one in a big box store. Did you buy this from a specialty cactus seller?
Nice plant!
Definately M. baumii. I've got one, and they are exactly similar. Mine is 6 years old this summer. A very nice attractive Mammillaria.
