Mammillaria vetula subsp. gracilis (Syn. M. gracilis var. fragilis)-Thimble Cactus

Mammillaria vetula subsp. gracilis (Thimble Cactus) after I brought it home on 4-20-13, #144-7.

Thimble Cactus

Mammillaria vetula subsp. gracilis

mam-mil-AR-ee-uh VET-uh-luh GRASS-il-is


Mammillaria vetula

Commonly sold as:

Mammillaria gracilis var. fragilis

mam-mil-AR-ee-uh GRASS-il-is FRAJ-ih-liss

Other synonyms of Mammillaria vetula from Plats of the World Online (24) (List last updated on 11-8-20): Cactus gracilis (Pfeiff.) Kuntze, Cactus pulchellus (Salm-Dyck) Kuntze, Cactus regius (C.Ehrenb.) Kuntze, Cactus vetulus (Mart.) Kuntze, Chilita fragilis (Salm-Dyck ex K.Brandegee) Orcutt, Chilita vetula (Mart.) Orcutt, Escobariopsis gracilis (Pfeiff.) Doweld, Escobariopsis vetula (Mart.) Doweld, Krainzia gracilis (Pfeiff.) Doweld, Mammillaria fragilis Salm-Dyck ex K.Brandegee, Mammillaria gracilis Pfeiff., Mammillaria gracilis var. fragilis A.Berger, Mammillaria gracilis var. pulchella (Salm-Dyck) Salm-Dyck, Mammillaria gracilis f. pulchella (Salm-Dyck) Schelle, Mammillaria grandiflora Salm-Dyck, Mammillaria kuentziana P.Fearn & B.Fearn, Mammillaria magneticola J.Meyrán, Mammillaria pulchella Salm-Dyck, Mammillaria regia C.Ehrenb., Mammillaria vetula subsp. gracilis (Pfeiff.) D.R.Hunt, Mammillaria vetula subsp. lacostei Plein & Heinr.Weber, Mammillaria vetula subsp. magneticola (J.Meyrán) U.Guzmán, Neomammillaria fragilis (Salm-Dyck ex K.Brandegee) Britton & Rose, Neomammillaria vetula (Mart.) Britton & Rose

***Although there are differences, Plants of the World Online by Kew lists Mammillaria vetula subsp. gracilis as a synonym of Mammillaria vetula. According to descriptions, Mammillaria vetula has 1-2 central spines and 25 radial spines where Mammillaria vetula subsp. gracilis has NO central spines. My plants have no central spines so I am continuing to acknowledge the subspecies. It’s my site and I can call it what I choose as long as the name was validly published, which it was in 1997. 

Mammillaria vetula Mart. is now considered the correct and accepted scientific name. It was named and described as such by Carl (Karl) Friedrich Philipp von Martius in Nova Acta Physico in 1832.

Mammillaria vetula subsp. gracilis (Pfeiff.) D.R.Hunt is now considered a synonym of Mammillaria vetula. This subspscies was named and described as such by David Richard Hunt in Mammillaria Postscripts in 1997. It was first named Mammillaria gracilis Pfeiff. by Ludwig Karl Georg Pfeiffer in Gartenzeitung in 1838.

Mammillaria gracilis var. fragilis A.Berger was named and described by Alwin Berger in Kakteen in 1929. This name is what the industry is commonly using…

The genus, Mammillaria Haw., was named and described by Adrian Hardy Haworth in Synopsis Plantarum Succulentarum in 1812. According to Plants of the World Online by Kew, there are 164 accepted species in the Mammillaria genus as of when I am updating this page on 11-7-20. That number is likely to change as updates are made.

There are links at the bottom of the page for further reading.

Mammillaria vetula subsp. gracilis on 6-1-13, #151-52.

This was my first Mammillaria so I was anxious to see how we got along. When temps warmed up enough I moved this cactus outside with the rest of the plants then I put it in a larger pot.


Mammillaria vetula subsp. gracilis on 7-30-13, 165-43.


Family: Cactaceae
Origin: Mexico
Zones: USDA Zones 9a-11 (20 to° F)
Size: 6” or so tall
Light: Sun to part shade
*Soil: Fast-draining. Potting soil amended pumice or perlite and grit
Water: Average during the growing period, barely in winter
Flowers: Pale to bright yellow

*There are many cactus and succulent recipes online. I used 2 parts Miracle Grow or Schultz potting soil with 1 part additional perlite and 1 part chicken grit for many years. Many cactus and succulent enthusiasts recommend using pumice in place of perlite and grit. I began using a mixture of about 50/50 Miracle Grow Potting Soil and pumice in the Fall of 2018 with favorable results. I repot any time of the year as necessary but I have found that repotting in the fall keeps their soil nice and loose for the winter.

You can read my Cactus Talk & Update and Cactus & Succulent Tips to get my opinion about growing cactus and succulents.


Mammillaria vetula subsp. gracilis on 8-23-13, #178-62.

The Thimble Cactus is a very easy plant to grow if you follow a few simple rules. They don’t mind regular watering during the summer months, but to much water in the winter is NOT a good idea. I just water my cactus maybe once or twice during the winter if at all. When I water my cactus and succulents during the summer, I just go over them with the wand one time. The other plant’s pots get filled to the rim.


Mammillaria vetula subsp. gracilis on 9-17-13, #188-44.

Information online says that this plant does well in full sun to part shade. When you move your plants outside for the summer, they need to get used to more light gradually. I normally place mine in light to part shade at first then gradually slide them over on the table to get more light. If they show any sign of burn, I put them back in more shade. I think I kept this cactus on the table behind the shed in more shade all summer.


Mammillaria vetula subsp. gracilis from the top on 9-30-13, #192-6.

Once in a while I will notice one of the balls of thorns has fallen off on the table. I just put it back in the pot where it can take root. That is actually how they spread in the wild.


Mammillaria vetula subsp. gracilis on 6-1-14, #228-59.

We made it through the 2013-2014 winter just fine and it was glad to be back outside again.


Mammillaria vetula subsp. gracilis on 7-12-14, #231-70.

I really enjoyed this plant as a companion, but unfortunately, I gave up most of my plants after the above photo was taken. I am back collecting plants again, so maybe someday I will bring home another Mammillaria vetula subsp. gracilis.


Mammillaria vetula subsp. gracilis on 9-13-18, #507-22.

I found this cactus at Wagler’s Greenhouse when I took plants there in September. It was unlabeled but I was sure it was a Mammillaria. I wasn’t sure what species it was at first because I was used to seeing them sold in clusters and not as a single specimen.


Mammillaria vetula subsp. gracilis on 10-10-18, #519-53.

I had to move the potted plants inside for the winter on October 10 because the forecast was calling for an “F” in a few days and the nighttime temperatures were getting cooler. I usually measure the cactus and succulents when I bring them inside. This plant measured 2 1/4″ tall.


Mammillaria vetula subsp. gracilis on 11-29-18, #534-30.

November 29 was a nice spring-like day, so I took the cactus to the back porch for a photoshoot. I was working on a post to show the difference between the cactus in my collection.


Mammillaria vetula subsp. gracilis close-up on 12-1-18, #535-22.

The species, Mammillaria vetula, has 1-2 central spines and at least 25 radial spines. The subspecies often lacks the central spines and only have 11-16 radial spines.


Mammillaria vetula subsp. gracilis on 6-22-19, #593-36.

The potted plants made it through the winter and once evening temperatures warmed up I moved the potted plants back outside for the summer. I moved the cactus to the back porch where they could receive full sun. The Mammillaria vetula subsp. gracilis had grown lots of offsets.

I was fairly busy during the summer so I didn’t take many photos. All the plants did very well despite a little neglect.


Mammillaria vetula subsp. gracilis on 10-13-19, #641-4.

I had to bring the potted plants inside on October 11 because an “F” was in the forecast. I always take photos of the plants as I bring them inside and measure the cactus and some of the succulents but I forgot to photograph this one so I did it on the 13th. It measures 2″ tall and most of its offsets have fallen off.


Mammillaria vetula subsp. gracilis with a bud on 11-23-19, #655-5.

I was surprised to see a couple of buds on this cactus on 11-23-19.


Mammillaria vetula subsp. gracilis flower on 11-30-19, #657-4.

This particular cactus will be interesting to watch grow because it started out as a single plant and I will get to watch it multiply. I just have to keep an eye on the offsets when they fall off to make sure they don’t blow away or fall off on the ground during the summer.


Mammillaria vetula (subsp. gracilis) at 1 3/8″ tall on 10-15-20, #747-82.

I had to move the potted plants inside for the winter on October 15 because an “F” was in the forecast. As always, I took photographs and measurements as I brought them inside. The Mammillaria vetula subsp. gracilis did very well over the summer and measured 1 3/8″tall when I brought the plants inside.  It has several kids still attached although many have fallen into the pot…


Mammillaria vetula (subsp. gracilis) with a flower and several buds on 11-6-20, #755-6.

I took a few more photos of some of the Mammillaria flowering in my small collection on 11-6-20 for a new post. It s always funny to see this plant flowering when it is so small.

I hope you enjoyed this page and maybe found it useful. If you have any comments, questions or suggestions, I would like to hear from you. Please click on “like” if you visited this page. It helps us bloggers stay motivated. 🙂 You can check out the links below for further reading. They take you directly to information about the species.


Please leave a comment. I would like to hear from you.

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.