If it is a escorbria or a coryphantha it wil have a line (a grove) on the tubercles on the top side. Tubercles are the bumps or nipples that have the spines growing at the ends. This grove should start from the body of the cactus a long the tubercles to the spines. Then you will know you have escorbria or a coryphantha sp.
If it is a mammillaria sp. prick with a pin and it should bleed a milky latex sap. Also if it flowers around the sides it may be a mammilaria sp.

I am not sure what kind it is, but it could be one of the three?

Thanks Aaron. I'll take a good look at it.

Regards,
Jay

Hey Aaron,

What has been your lowest temp so far? I have hit -19 C (-2.2 f) during our cold snap. It's warmer now with overnight lows above freezing. 😀

Regards,
Jay

So far it has been above sub 0 here. It did get close to 0 with that last cold front, I have a low of 2.1 f. so far this year 😀 , but some of my plants have cold damage 🙁 I think it is because it was so warm here this fall, then one night the dropped to 7.5 and did not warm up much after. I think the plants had no time to adjust to the cold this year 😯

I always think the worst this time of year, I do it every year! I think most every thing should be ok!

I think we have had it for the cold. Temps should be above freezing now. Maybe the odd night it might drop. Now that i said this we will probably have another cold snap with blizzard conditions. LOL

Let me know how your plants do.

Regards,
Jay

Sounds like it is warmer at night over there. Here the days start to warm into the upper 30's and lower 40's, but it is still in the teens at night here. It will drop into the teens and 20's here until march, but not every night 😀

A little warmer but it's been above normal for this time of year. I think we have about the same temps. 😀 How far are you from Boise?

Regards,
Jay

Oh, about 110 miles east of Boise. Sometimes the weather here is night and day compared to Boise, it is always warmer in the western part of the state. I really miss my warm zone 7, when I lived on the snake river south of Boise 😥 You may not find that zone 7 on a map, but it is there 😉