3. looks like Mammillaria geminispina ssp leucocentra to me (one I posted for ID a while back~but not positive on it). Link to one below.

For Photobucket thumbnails, put a checkmark in the box (underneath) for the photo you want. Scroll down to bottom of page & click to select the generate HTML deal, then Go. On new page click on the 1st URL listed to highlight & then copy it (right click-copy). Come back to your post & paste it in. (That's the SHORT version of How To--think there might be instructions at the site somewhere.)

~Rosemarie

Here is a link that might be useful: {{gwi:461462}}

What about Mammillaria columbiana for #2 and Mammillaria rhodantha for #4
Alfonso

Rosemarie, the link you gave looks right for #3. Thanks.

Alfonso, I looked up columbiana and rhodantha and #4 seems to look more like columbiana - doesn't rhodantha have distinct red spines? Maybe #2 and #4 are the same thing?

Jan

So are we all agreed that #1 is M. marksiana?

#2 Not M. nivosa. Looks to me like M. columbiana, which happens to be native to Jamaica :)

#3 might be M. geminispina, but I don't think it is ssp leucocentra. Also the tubercles look angular rather than rounded, but that might just be the photo?

#4 might also be M. columbiana. M. rhodantha has recently had all sorts of other species lumped into it, some have reddish spines and some don't, but I'm fairly sure this isn't M. rhodantha.

OK, so it seems they got my account back up so I'm back to being me.

S&B - Didn't know that Jamaica had any native mammillaria. Maybe I need to do some more research. I know that nivosa is supposed to be native to Cuba and #2 looked more like a nivosa to me when it was smaller.
- #3 tubercules are more angular than rounded. And therefore???

Jan

Try Mammillaria albilanata for #3.

M. columbiana is the only recognised species from Jamaica, although there are recent published reports of a different (un-named) species also occurring there.

M. nivosa has generally a single central spine which is almost identical to the rather thick and yellow-brown radials. Your plant(s) appear to have five-ish yellow centrals and a number of thinner paler radials.