New cactus from Wal-Mart after I brought them home on December 2 (2020). I identified the plant on the right front as Gymnocalycium baldianum (Dwarf Chin Cactus), and the one in the rear on the right as Mammillaria nivosa (Wooly Nipple Cactus). The two on the left… Mammillaria ?.

Hello Everyone! I hope this post finds you well. I went to Wal-Mart on December 2 to do a little shopping but mainly because I needed more saucers to go under pots. A lot of the old ones had gotten worn out plus I needed a few more. While I was in the plant department I decided to check out the “cactus corner” where they keep the cactus and succulents. As usual, they were over watered and otherwise neglected. Anyway, I found four that I decided to bring home.

I knew one was a Gymnocalycium and the other three were Mammillaria species. The label on the side of the pots…

The labels were mostly uninformative and basically just said “CACTUS” with a little growing information. Labels like that don’t give you much to go by. Even if there was an outdated name it would have been much better. The grower is the same as the last plants I bought at Lowe’s. Finding their correct names is a lot more difficult especially when it comes to Mammillaria… They were in 3 1/2″ pots, though, and all had plenty of room to grow.

Gymnocalycium baldianum (Dwarf Chin Cactus) at 1 1/6″ tall x 2″ wide on 12-2-20, #767-2.

The Gymnocalycium was fairly easy to identify because I already have a G. saglionis (Giant Chin Cactus) that I had brought home from Lowe’s in March of 2019. It is a great plant, so bringing this one home was a no-brainer. With only 61 species to choose from in the genus, it wasn’t that difficult to figure out this plant was a Gymnocalycium baldianum commonly known as the Dwarf Chin Cactus. It is very small at only 1 1/6″ tall x 2″ wide.

Gymnocalycium baldianum (Speg.) Speg. is the correct and accepted scientific name for this species of Gymnocalycium. It was named and described as such by Carlo Luigi (Carlos Luis) Spegazzini in Anales de la Sociedad Cientifica Argentina in 1925. It was previously named described as Echinocactus baldianus by Mr. Spegazzini in Anales del Museo Nacional de Buenos Aires in 1905. The International Plant Names Index (IPNI) has more than 2,700 records for plant names of which Mr. Spegazzini is either the author, co-author, or involved in the basionym.

The Dwarf Chin Cactus is a native of the Catamarca Province of Argentina where it grows in a fairly restricted range. Its major threats are collection and fires.

Gymnocalycium baldianum (Dwarf Chin Cactus) on 12-2-20, #767-3.

This species is rather small, growing to only 3-4″ tall x 3-5″ wide, and can be grayish-brown to blue-green, sometimes almost bluish-black. They have 9-10 rather broad ribs with prominent tubercles divided by deep axils. The areoles on the end of the tubercles have a small tuft of wool and 5-7 very short, somewhat recurved,  radial spines. It looks like there is a smile between each tubercle… There is a name for that but I forgot what it… I read about that as a distinguishing feature of another species. 🙂

Gymnocalycium baldianum (Dwarf Chin Cactus) on 12-2-20, #767-4.

The apex of the plant is concave or “sunk-in” which is a pretty neat feature of most cactus. As plants grow, they just kind of unfold. Always constantly moving, but every so SSSSLLLLOOOOWWWWLLLLYYYY…

Gymnocalycium baldianum has received the Royal Botanical Society’s Award of Garden Merit. 

Mammillaria nivosa (Wooly Nipple Cactus) at 1 3/4″ tall x 2″ wide after I brought it home on 12-2-20, #767-13.

The second plant that was fairly easy to identify was the Mammillaria nivosa whose common name is Wooly Nipple Cactus. It was easy to identify because I put photos on a Facebook Group and a member told me what it was. I didn’t feel like going through Mammillaria photos to figure it out. Most of the photos show their flowers and not the plant itself… This plant is 1 3/4″ tall x 2″ wide and can grow up to 10″ tall.

This species is fairly unique because of where it is native. While most cactus are native of Mexico through South America, this one is found on several islands in the Caribbean. Its native habitats are declining due to urbanization and tourism but it is also found on Mona Island which is a protected nature reserve.

Mammillaria nivosa Link ex Pfeiff. is the correct and accepted scientific name for the Wooly Nipple Cactus. It was named and described as such by Louis (Ludwig) Karl Georg Pfeiffer in Enumeratio Diagnostica Cactearum hucusque Cognitarum in 1837. It had previously been named and described by Johann Heinrich Friedrich Link but his description wasn’t validly published. Mr. Pfeiffer then used his name and description giving Mr.Link the credit.

Mammillaria nivosa (Wooly Nipple cactus) on 12-2-20, #767-14.

In the wild, Mammillaria nivosa can be found as solitary plants, but usually grows in colonies and readily offsets to form a small mat. Plants are dark green but turn a bronze color in more sun. Plants are globe-shaped and cylindrical with obtusely conical and laterally compressed tubercles.

Mammillaria nivosa (Wooly Nipple Cactus) on 12-2-20, #767-15.

Its tubercles have wooly areoles that usually produce one central spine and 6-13 radial spines. The spines are bright yellow to dark brown and are approximately 1 1/2″ long, point away from the stem, and are VERY stiff and sharp. There is ample wool in the axils between the tubercles as well. This plant does well in sunny to partly shady areas, but bright light is supposed to bring out the bronze color, encourage flowering, and heavy wool and spine production…

NOW FOR THE OTHER TWO PERPLEXING PLANTS…

One of the members on the Facebook group suggested the other two were Mammillaria hahniana. My thoughts and reply were, “I already have a Mammillaria hahniana and it looks nothing like these two.” I posted a photo of my Mammillaria hahniana and received several “likes”. No one else had any other suggestions so after a few days I posted photos on three other Facebook groups. NOTHING. I was pretty surprised no one had any other suggestions. That never happens! SO, I revisited my Mammillaria hahniana page and went to the description on Lifle (Encyclopedia of Living Forms). There were also quite a few photos online that sort of revealed my screw up… Mammillaria hahniana is A “VARIABLE” species. OH, I had already sent photos to Daiv Freeman of the CactiGuide explaining the ordeal and I received no reply from him either. That also never happens. It was like his silence was telling me I had it already figured it out. GEEZ! The reality of having brought home two more Mammillaria hahniana was setting in… The goal is to collect more species not more of the same… You can clearly understand how that can happen when there are “variables” involved. All three plants are completely different… After thinking about it, I was OK with having three Mammillaria hahniana, since they show the variations of the species. I named them Unos, Dos, and Tres. 🙂

Mammillaria hahniana (Old Lady Cactus) #2 (Dos) at 1 3/4″ tall x 2″ wide on 12-2-20, # 767-6.

The first one in question, Dos,  is sort of club-shaped and a darker green. It measured 1 3/4″ tall x 2″ wide and is very hairy…

Mammillaria hahniana (Old Lady Cactus) #3 (Tres) at 1 1/8T tall x 2″wide on 12-2-20, # 767-10.

Tres is shorter than Dos at 1 1/8″ tall but it is also 2″ in diameter. When I measure cactus I ignore the spines and focus on the body (stem) of the plant. Tres is kind of squat and globe-shaped like a pumpkin. It is kind of more bluish-green in color which can throw you off a little… The Mammillaria muehlenpfordtii in my collection is a bluish-green and AWESOME!

Mammillaria hahniana (Old Lady Cactus) #2 (Dos) on 12-2-20, # 767-7.

From the above close-up of Dos, you can see hairs, wool, and spines. There is just a little speck of wool growing from the axils between the tubercles. Some of the “hair” is also coming from the axils but you have to get a magnifying glass to tell. The areoles on the tip of the tubercles have 1-4 very short central spines and 20-30 hair-like radial spines… Some are very short and others VERY LONG. Information on Llifle says these hair-like spines can be from 5-15 mm long which is just over 1/4″ to just over 1/2″. Some of the longer hairs on this plant are nearly 1″ long which I think are coming from the axils. Dos has more of a flat top similar to Unos…

Mammillaria hahniana (Old Lady Cactus) #2 (Dos) on 12-2-20, # 767-8.

The apex of Dos (#2) is clearly concaved with a lot of wool in the center. The areoles also have more wool around the top of the plant but seem to disappear somewhat farther down the stem (as the plant grows).

Mammillaria hahniana (Old Lady Cactus) #3 (Tres) on 12-2-20, # 767-11.

Tres has A LOT more and larger tufts of wool in its axils, especially around the top, and its hair is not as long.

Mammillaria hahniana (Old Lady Cactus) #3 (Tres) on 12-2-20, # 767-12.

From the top, Tres looks A LOT different than Dos. The concaved apex is barely visible from all the wool. The hair-like radial spines and axil hair give Tres a cobwebby appearance.

The Mammillaria hahniana trio. Unos in the back, Dos on the right, and Tres on the left on 12-5-20, #768-1.

Once I came to the conclusion that it was definitely possible the two new Mammillaria were M. hahniana, I took all three plants to the back porch for a photoshoot. I brought Unos home from Wal-Mart on February 1, 2016, when it was just 1 7/8″ tall x 2 3/8″ wide. On October 15 (2020) when I moved the plants inside it measured 3 5/8″ tall x 3 5/8″ wide.

Mammillaria hahniana Unos, Dos, and Tres from the top on 12-5-20, #768-2.

From the top view, Unos, Dos, and Tres look nothing alike. You can certainly tell how someone would think they are three different species. Am I sure they are all three Mammillaria hahniana? NOPE! Unfortunately, the description of Mammillaria hahniana fit all three. Umm, the two smaller ones more than Unos. Unos has transformed into a massive ball of wool!

Click on Mammillaria hahniana to view “their” page…

The next post will be short, but I have a big surprise coming in the mail very soon…

Until next time, stay well, be safe, stay positive. Always count your blessings and give thanks. You are unique and special. If you can and are able, go outside and get dirty!