Hello everyone! I hope this post finds you well. This post is about the Mammillaria species in my small collection of cactus. Mammillaria species come in all shapes and sizes and are very easy to grow and some flower off and on throughout the year. I took most of the photos in this post on October 15 as I was bringing the plants inside, but I had to take a few more on November 1 and 6… The longer it takes to finish this post the more photos I will probably take because of the flowers…

Plants of the World Online currently lists 164 species in the Mammillaria genus, which is up two from my last update. Although The Plant List is no longer maintained, even though it is still online and viewable, listed 185 accepted species, 93 accepted infraspecific names (varieties and subspecies), a total of 519 synonyms, and 448 unresolved names. So many species were given a multiple of scientific names over the years and it was quite an undertaking to resolve the issue. It will no doubt be a continual work in progress, even as new species are added. The Mammillaria genus alone has 20 synonyms… That is 20 previous genera whose species have been transferred to Mammillaria or attempts made to relocate them.

So, why do I like Mammillaria species? For one, there are a lot to choose from, they are easy to grow, they come in a wide variety of sizes and shapes, many freely flower, and some are just downright weird. All Mammillaria have one particular thing in common that makes them stand out. They have pronounced tubercles arranged in a particular manner, kind of looks like they are spiraling upward… If you have a cactus with pronounced tubercles, it is very likely a Mammillaria.

If you want further information about any of the Mammillaria in this post, or to see more photos, click on their name under the photos in green. That will take you to their own page.

Here we go…

<<<<Mammillaria decipiens (subsp. camptotricha)>>>>

I brought this AWESOME Mammillaria decipiens subsp. camptotricha (Bird’s Nest Pincushion) home from Wal-Mart in March 2018 because it was weird and I didn’t have one. It has done very well over the summer and the tallest plant in the pot was 1 3/4″ tall and the cluster measured 4 1/4″ wide on October 15. Like all cactus, they swell and shrink as water is available. I watered the cactus the day before I brought them inside because I thought they would swell somewhat before I took measurements. Apparently, I should have done it several days before that… Sunday, as I was taking photos of few of the Mammillaria with flowers, I noticed the biggest one in this pot looked bigger than before. SO, I went and got the tape measure and it was 2″ tall! GEEZ! That’s 1/4″ taller than it was on the 15th!

That isn’t the first time that happened. When I was writing the post Cactus Talk & Update… OUCH! in December 2018 several had done that. They hadn’t been watered since October but they were swelled up.

Getting back to the Mammillaria decipiens… It was cramped up in a 2 3/4″ diameter pot when I brought it home and the cluster of plants was 1 1/2″ tall x 3″ wide. The pot was literally bulging and the plants were hanging out over the top somewhat.

After doing a little research, I found out this cactus was a subspecies called Mammillaria decipiens subsp. camptotricha. The species has 5-11 radial spines per tubercle that are a whitish color and the spines are shorter. The subspecies have 4-5 radial spines per tubercle that are longer and bristly… Describes the one I brought home perfectly. BUT, “those in charge” have decided the subspecies is a synonym of the species. HOWEVER… Since the subspecies name was validly published in 1997, I can go ahead and use it if I choose. 🙂

This species got around A LOT and has 19 synonyms covering seven genera…

<<<<Mammillaria elongata>>>>

Hmmm… As you can tell, the Mammillaria elongata (Lady Finger Cactus) is doing well. This has been an interesting cactus and I have had no issues with it. We got off to a rocky start but that was my fault. This plant, or cluster of plants, was stuffed into a small pot which I accidentally knocked off on the floor a few days after I brought it home in March 2018. Of course, most of the offsets fell off. I stuck them back in the small pot the best I could at the time. It had no side effects and didn’t even get upset. To say this species freely offsets would be an understatement. Even the kids have kids…

On October 15 when I brought the plants inside, the longest or tallest, umm… The main stem in the center, the mother plant, measured 6 1/8″ long, or tall, whichever you prefer. The entire cluster was 7″ wide. After I remeasured the Mammillaris decipiens I wondered about this plant. In fact, last year it was over an inch longer in November than it was in October, up to 7 3/8″! This time it is 6 1/8″ long??? I remeasured it again when I was putting the measurements on the journal and it definitely was 6 1/8″. So, for the heck of it, I remeasured it AGAIN as I am writing this post. Hmmm… 7 3/4″!!! Believe it or not, I do know how to use a tape measure and I am not going to fall for this Mammillaria conspiracy. They did this to me last year…

<<<<Mammillaria hahniana>>>>

Several Mammillaria species have a lot of wool like the Mammillaria hahniana (Old Lady Cactus). I have had this cactus as a companion since I brought it home from Wal-Mart on February 1, 2016. It was only 1 7/8″ tall x 23/8″ wide when I brought it home now it is 3 5/8″ tall x 3 3/8″ wide. NO, I am not going to measure it again to make sure…

The Mammillaria hahniana is quite a bloomer and may surprise you anytime throughout the year. Most Mammillaria species are sort of concave at their apex and their spines just kind of unfold as they grow. Mammillaria hahniana is sort of flat-topped and you can clearly see how concave it is in the center. This species is rather globe-shaped when young but can become more columnar with age. Over time they can form good-sized colonies but I don’t think they divide dichotomously.

I had to take the above photo on November 6 because it has more buds. It will continue growing more, maybe in 2-3 rows. Llifle (Encyclopedia of Living Forms) lists several subspecies and varieties of Mammillaria hahniana but none are currently accepted even though they were once validly published. They all have certain peculiarities in the quantity and size of spines (central and/or radial), wool, flower color, etc. One even has white flowers. While it may be true they are the same species, these characteristics set them apart so I personally think the intraspecific names should be used to distinguish them from one another. When young, they might look very similar, but these different “features” become more pronounced with age.

<<<<Mammillaria karwinskiana>>>>

The Mammillaria karwinskiana (Silver Arrows) is a great little cactus that has gotten more wooly since I brought it home from Lowe’s on 9-21-18. It was 1 7/8″ tall x 2 3/16″ wide when I brought it home and now it is 3 5/8″ tall x 3″ wide. If you find this plant at Lowe’s or Wal-Mart it is likely to be labeled Mammillaria nejapensis which is a synonym. In fact, this species has 60 synonyms!!! Ummm… There were only 45 the last time I updated its page last December. GEEZ!!! Where did they all come from? OH, I know… POWO has been uploading a lot of names from the International Plant Names Index (IPNI) they didn’t have in their database. Maybe that’s why…

The tufts of wool on the Mammillaria karwinskiana reminds me of tiny rabbit’s feet (you know, the rabbit’s foot keychains).

It started flowering more shortly after I brought it inside. I am glad its flowers aren’t pink… Maybe this one is a guy.

<<<<Mammillaria muehlenpfordtii>>>>

I really like this Mammillaria muehlenpfordtii (Golden Pincushion) with its club-shape. I brought it home from Lowe’s when it was 3 1/4″ tall x 2 1/8″ wide in September of 2018. It had fallen over on the discount rack and was completely out of its pot. I picked it up and looked at it, put it back in its pot, then put it in my cart. There was barely any soil left because it had fallen out and onto the floor. This plant likely would have been thrown out and I certainly couldn’t let that happen… I liked its shape, its silver-bluish-green color, and the combination of very long and short spines. Sounded like a win-win for both of us so I bought it home.

The label said it was a Mammillaria celsiana but that species has been determined to be a synonym of Mammillaria muehlenpfordtii. This is one of several Mammillaria I now have in my small collection that divides dichotomously. That means the plant itself becomes two, then two becomes four, and so on. Well, the information says they do that when they “mature” which I have no idea when that will be. 🙂 Until they divide, they are said to be a solitary species. It doesn’t seem to mind its neighbors, though. They are always teasing the cats, trying to get them to jump on their table…

Information I have read says this is a summer bloomer but it is flowering now like it did last October. If it bloomed in the summer I missed it. Some Mammillaria flower just about anytime during the year. I told him “guys aren’t supposed to like pink.” He replied, “Who said I am a guy?” GEEZ! Some Mammillaria species are a bit of a smart aleck…

<<<<Mammillaria mystax>>>>

The Mammillaria mystax is a very neat and tidy cactus that hails from central and southwest Mexico. Ummm… There is still no common name given for this cactus. It has done very well since I brought it home from Lowe’s on September 21, 2018. It has grown from 1 3/4″ tall x 2 1/4″ wide to 2 3/4″ tall x 2 3/4″ wide. Even in nature, this species only grows to 6-8″ tall.

I think it is odd how the central spines close to the top are longer than the central spines farther down. Do they shrink as the plant grows or does it grow longer spines as it matures? I am learning that some species of Mammillaria change quite a bit as they age which led to many subspecies and variety names. I know, I know… I am repeating myself. Mammillaria have a tendency to make one talk to themself.

Mammillaria mystax has 28 synonyms now. The featured image on Llifle (Encyclopedia of Living Forms) for Mammillaria mystax shows a cactus that was formerly Mammillaria casoi with long, entangled spines… Supposedly, this species is highly variable. Hmmm… I don’t get it but I guess I don’t have to understand to be confused. 🙂

Hmmm… Still, no sign of flowers or buds but it is still a neat plant. Look at those spines! I like it because it is such a neat little ball of thorns plus I have to find out what this one will do as it matures…

<<<<Mammillaria plumosa>>>> 

The Mammillaria plumosa (Feather Cactus) is quite a neat clump of fuzz. I bought this cactus from an Ebay seller in September 2018 and I will never forget how it arrived. It was like a little ball all wrapped up in toilet paper. The cluster was only 2 1/4″ wide and the largest plant, the big one in the middle, was only 3/4″ tall. It has done quite well and now the biggest plant is 1 3/8″ tall and the cluster is 3 1/4″ wide. Or at least it was on October 15. It is a VERY slow spreader and I think I can barely see two very tiny offsets starting to peak through.

I took a couple more photos of the Mammillaria plumosa to show its flowers.

This hole has been here for a while and I think it is where a flower was last year. Maybe I need to comb it. 🙂

If you ever get a chance to get one of these, I think you will like it. Check on Ebay.

<<<<Mammillaria pringlei>>>>

The Mammillaria pringlei (Lemon Ball Cactus) is the third oldest Mammillaria in my collection. I brought it home from Lowe’s on April 24, 2017, but apparently, I didn’t measure it until October 17 when I moved the plants inside for the winter. At that time, it measured 4 1/2″ tall x 3 1/2″ with the spines. Since 2018, I always measure the cactus body and ignore the spines he best I can. Anyway, this cactus always does well and on October 15 it measured 5 3/4″ tall x 2 1/2″ wide. Hmmm… That is the same width as last year BUT I am not going to remeasure it now because I have a sneaky suspicion it will be different. I don’t want to get caught up in remeasuring the Mammillaria again, even though I am curious… Maybe I can do it when they are sleeping so they won’t say, “AH HA! I knew you couldn’t resist.” 🙂

Mammillaria pringlei is quite a bloomer. It flowers off and on during the summer but really puts on a show in the fall.

Mammillaria pringlei is one of the only species of Mammillaria with yellow spines. They look more white in the photo because of the light.

I took another photo of the Mammillaria pringlei on November 1. I just had to do it. She asked, “where is your tape measure? Hiding in your pocket?”

This species was once considered a subspecies of Mammillaria rhodantha (next one on the list) then included in the Mammillaria rhodantha Group…

<<<<Mammillaria rhodantha>>>>

Mammillaria rhodantha (Rainbow Pincushion) is quite a cactus! Its reddish spines make it a very attractive show-stopper. This was one of my first cactus from Wal-Mart when I started rebuilding my collection of plants in 2016. Until then, I previously had quite a few succulents but not that many cactus. I realized that many succulents I had in Mississippi where I had five sunrooms did not like the low light during the winter here. SO, when I started collecting plants again I went for more cactus because they can handle low light during the winter. I didn’t measure the Mammillaria rhodantha when I first brought it home from Wal-Mart on February 1, 2016, but it was 3 3/4″ tall x 3″ wide (including the spines) on October 17. On October 15 when I brought the plants inside it measured 4 1/4″ tall x 2 5/8″ wide. Hmmm… That is a little shorter than last October when it measured 4 1/2″ tall. Like I mentioned, that is probably because I watered the cactus the day before and they hadn’t “swelled” yet. Even in the wild, Mammillaria rhodantha only grows from 6-12″ tall, so it likely grows fairly SSSSLLLLOOOOWWWW.

The species is variable and some Mammillaria rhodantha have yellowish or whitish spines.

The Mammillaria rhodantha typically flowers from spring through fall, but this one didn’t flower well until last year. It seemed to be loaded with buds at times but they never grew or opened. Other species in my collection start flowering in one spot then kind of go around the circle. This one will produce buds but the flowers open without a system.

My last update of this species own page was in November 2019 when Plants of the World Online listed 115 synonyms of Mammillaria rhodantha. Now there are 132!!!  78 species are other Mammillaria that were decided were actually Mammillaria rhodantha. There are 35 varieties, subspecies, or forms of Mammillaria rhodantha named that were once valid accepted names. An additional 54 are from when some of those infraspecific names were species in other genera as well as Mammillaria, some fairly recent and some very old names. That doesn’t include names that were not validly published… Mammillaria pringlei was also once considered a subspecies of Mammillaria rhodantha, and apparently, there are variants of it with yellow and whitish spines… Hard to explain it, but there are, or were, six other genera that many species of Mammillaria were in at one point. Heck, most of the older named species in any genera of cactus started out in the genus simply called Cactus…

<<<<Mammillaria vetula (subsp. gracilis)>>>>

The Mammillaria vetula (subsp. gracilis) (Thimble Cactus) is hanging in there to be a good parent. Some of its kids stayed attached better the past summer and the ones that fell off are taking root. This is “one of those” you have to handle with care but not because of its spines. The offsets fall off very easily which is why one of its past scientific names, “fragilis”,  was very appropriate. I had a fairly large pot of this one before, but I hadn’t really been to Lowe’s or Wal-Mart that much to find another one. When I did go to Lowe’s and was looking for one like before, I choose the “Arizona Snowcap’ (below) instead. Then when I went to Wagler’s Greenhouse to take plants in September 2019, I noticed a very small cactus with a few tiny offsets sticking out of it. I looked at it and realized it was a Mammillaria but it didn’t quite look familiar. Well, I brought it home and it turned out to definitely be a Mammillaria vetula subsp. gracilis. I was always used to seeing them available in clusters not as a single specimen. It did perfectly fine over the winter and the next summer and grew quite a bit, well, the offsets did. By the time I moved the plants inside for the winter, most of its offsets had fallen off. Then it was a little plant AGAIN! Fortunately, as I said, most of the offsets it grew since then have managed to stay attached. It measures only about 2″ tall which is pretty good considering… Umm… Considering it was 2″ tall last October. 🙂 Actually, to be honest, it was only 1 1/2″ tall on October 15 but I did measure it again a few days later and it had swelled to ALMOST 2″. 🙂 🙂

I had to get another shot of this plant on November 6 because it was waving its flower at me. It wants me to also tell you about the marble in its pot. After I brought it home from Wagler’s it kept growing toward the light and almost fell over SO, I put the marble next to it to hold it up. I was going to take it out of the pot, but apparently, it got so attached to the marble it wanted me to leave it. I guess it is like a pet rock or maybe it is afraid it will need it again…

Plants of the World Online lists Mammillaria vetula subsp. gracilis as a synonym of Mammillaria vetula (1832) even though there are differences. One difference is that Mammillaria vetula has 1-2 central spines and 25 radial spines. The subspecies does NOT have central spines. I choose to continue to use the subspecies name because it was validly published and accepted in 1997. It replaced the name Mammillaria gracilis (1838). The industry still sells this plant as Mammillaria gracilis var. fragilis which was named and accepted in 1929.

<<<<Mammillaria vetula (subsp. gracilis) ‘Arizona Snowcap’>>>>

The Mammillaria vetula (subsp. gracilis) ‘Arizona Snowcap’ did great over the past summer and now, FINALLY, is looking like this cultivar is supposed to again. When I found this cluster at Lowe’s on July 18, 2018 it was a 2″ tall x 5″ wide cluster of balls hanging over the sides of a 3 1/2″ diameter pot. The reason I chose this cultivar over the regular Mammillaria vetula subsp. gracilis was because many of the balls were covered with thick, white spines and I hadn’t seen any like it before. Well, it was just flat neat! I brought it home and took photos. Of course, I put the cluster in a larger pot. Over the next summer, 2019, the plants that were more white died off!  After I moved the plants inside for the winter I removed the dead plants and kind of spruced up the pot a little.

Fortunately, over the summer, the cluster is looking GREAT! As you can see in the above photo, one of the plants has a circle of buds.

I took another photo on November 6 after most of the flowers had opened. It is really neat to see such a small plant have a circle of flowers.

According to LLIFLE (Encyclopedia of Living Forms), this cultivar is a monstrous form, or mutation, of Mammillaria vetula subsp. gracilis that is not found in the wild. They say it is of garden or nursery origin and perhaps a hybrid…

Well, that’s it for the Mammillaria update and it only took about three days to finish. Seems like a week! 🙂 I can get the remaining 10 cactus and succulents in the next post.

Until next time, take care, be safe, stay positive, and always be thankful! I hope you are all doing well…