Hi, Does anyone know what this is? I'm guessing a Ferocactus or Mammillaria, but my guesses are so far off lately that I might as well guess a Giant California Redwood.
Thanks!

I don't think it a Ferocactus or Mammillaria. Because of the way the tubercles appear to be glued on, in combination with the black spines, I think its something odd like Copiapoa (but not necessarily that).

I think it is a Mammillaria, while I see why Daisy would say it might not be, I think it looks a lot like this particular Mammillaria:

http://www.agaveville.org/view...

Mammillaria melanocentra.

When it flowers you will be able to tell for certain.

Each node has exactly 10 spines. The center and 3 lower-pointing ones are black. They are proportionally longer than the spines of most cacti, and perfectly straight.

Looking at these that are mentioned I can see definite similarities, I just wish I were good at identifying cacti. I have a couple books but they are rather general; I also have several bookmarked sites that are great but with so many genera and (to my eye) lots of similarities between them - not to say anything of varieties - it is so hard to pinpoint. This one is rather small yet but I am hopeful it will bloom next year and that would help.

I have a bunch of Mammillaria books, most are very old and the nomenclature of these plants has changed (and is still changing) so much that it is hard to use any of them because you can often get multiple names for the same plant depending on which book you use.

A fairly recent one is the book 'Mammillaria' by Pilbeam, in it the entry for M. melanocentra sup melanocentra states that there are 7-9 radial spines of unequal length, with the lowest longest, they start black but with age turn pale grey with black tips. The central spine is much longer and stronger also black usually pointing somewhat upwards. Flowers are pink-carmine and will appear from between the tubercles - flowering is usually preceded by appearance of wool in between the tubercles.

I think that matches up pretty good. I am pretty sure I have two of these. I have had a hard time keeping them decent looking - these plants want plenty of root space, once I added them to larger multi plant bowl shaped pots they started doing better. I have no good pictures of them - something I will try to remedy.

This one is little right now - about 2 1/2 - 3" diameter. I potted it in a little Bonsai pot for right now - lots of room for roots. Like most babies it was in soil I don't like for succulents - it holds way too much water - so I made a mix that is very porous. I have several succulent leaves and a few cactus pups I just set on top of similar mixes and most are rooting nicely so I think this one will do well. Hopefully it will produce flowers and someone will be able to identify it perfectly.

I'm almost afraid to see how many plant names will change as DNA is used more for determining plant lineage. It will be nice having plants "better aligned" in taxonomy.

If its Mammillaria, at that size, it should bloom. That will answer a lot of questions really fast (the most important being 'what it is?')

I grow orchids (and cactus). You would be amazed at how fast names change in the orchid world with DNA testing and nomenclature aligning. I decided a long time ago to make note of name changes but not change the tag on my plants. I would give my plants identity crisises if I changed the tag everytime a new name came along.

I have a small collection of orchids as well; I know what you mean about name changes! I can go to different nurseries here and find exactly the same plant with different names and each place swears theirs is the correct name.

Something I find confusing is two plants that look different but have the same name. I'm told that is not unusual in hybrid cultivars if the "mother" is one and the "father" genre the other the resulting hybrid has one type/color of flower, and if the sexes are reversed the blooms look totally different, but the names remain the same? I wonder if botanists care how easily I can be confused without adding such monkey wrenches into the works! :smily:

Thanks for the heads up about blooming - I have been hoping it would sooner rather than later. I know I can wait until next spring or summer but I'm worse than a 6 year old at Christmas if I have to wait for years!

Here is a picture of one of my two M. melanocentra, and judge for yourself:

It certainly looks related. Except for the color & number of spines it looks the same doesn't it!

Great collection of cacti, Thijs! Nice picture!

Thanks!

The number of spines can fluctuate - so that would not be a disqualifier and the color is probably a combination of the flash I had to use to get a decent picture and the fact that this one is currently adjusting to the fact that the angle of the sun has changed not hat it is fall - so it is getting a little more sun as the overhang it is under is not quite as good at preventing the sun from reaching it. It is normally pretty much the same dark green color as yours.

Sorry, when I said color I meant the color of the spines not the cactus itself. The bodies look alike. I have plants that vary in color from how much sun they receive so I can understand the body can be a different shade from one to the next.