Old Lady Cactus or Old Lady Pincushion
ROYAL HORTICULTURAL SOCIETY AWARD OF GARDEN MERIT
Synonyms for Mammillaria hahniana (11): Mammillaria bravoae R.T.Craig, Mammillaria hahniana subsp. bravoae (R.T.Craig) D.R.Hunt, Mammillaria hahniana subsp. mendeliana (Bravo) D.R.Hunt, Mammillaria hahniana var. werdermanniana F.Schmoll ex R.T.Craig, Mammillaria hahniana subsp. woodsii (R.T.Craig) D.R.Hunt, Mammillaria mendeliana (Bravo) Werderm., Mammillaria saetigera Boed. & Tiegel, Mammillaria saetigera var. quadricentralis R.T.Craig, Mammillaria saetigera subsp. woodsii (R.T.Craig) Rogoz. & Plein, Mammillaria woodsii R.T.Craig, Neomammillaria mendeliana Bravo
Mammillaria hahniana Werderm. is the correct and accepted scientific name for this species of Mammillaria. It was named and described by Erich Werdermann in Monatsschrift der Deutschen Kakteen-Gesellschaft (Berlin) in 1929.
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 162 accepted species in the Mammillaria genus as of when I am updating this page on 12-23-19. Those numbers are likely to change.
I bought my Mammillaria hahniana from Wal-Mart on 2-1-16. It was n a 2 1/2” diameter (4 oz.) pot. The plant measured approximately 1 7/8” tall x 2 3/8” wide. The label states:
“Native to Mexico, forms globular stems to 6” or more in diameter. Stems are densely covered with white hair and short white spines. Concentric rings of pink flowers. Protect from frost. Provide bright light/sun. Hardy to 20 degrees F. To 6” tall. Water thoroughly when the soil is dry.”
Zones: USDA Zones 9a-11 (2- to 40° F)
Size: Small, maybe about 4-5” tall x 4” wide
Light: Sun to part shade
Soil: Fast-draining. Potting soil amended with grit and pumice or perlite.
Water: Average during the growing period, not necessary in winter.
Mammillaria hahniana is native to Guanajuato, San Luis Potosí, and Queretaro, Mexico. The species grows along relatively steep slopes in submontane matorral and deciduous forests. This cactus is locally common where it occurs, and grows in groups or clusters which are rare. Mammillaria hahniana is listed as near threatened in its native habitat because of its limited range and illegal collection. Some subpopulations are impacted by deforestation.
Many cacti are very slow growing so I take measurements from time to time. When I moved the plants inside for the winter on October 17, 2017, the Mammillaria hahniana measured 2 1/2″ tall x 2 3/4″ wide.
Remember to clean off your pots when you bring them inside for the winter. Remove dead leaves or other debris that might have collected in your pots and on your plants. Check for unwanted guests that may be trying to hibernate around the base of your plants because you never know…
I like taking photos from the top of the cactus. Many of them grow in this neat spiral-looking pattern.
Information online says that Mammillaria hahniana is one of the fastest growing of the Mammillaria genera and will form large groups. The wool is supposed to increase in thickness and length.
Mammillaria, like most cactus, are easy to grow if you follow a few basic rules. Check out my Cactus & Succulent Tips for my advice…
The Mammillaria hahniana is continuing to do well and is now happy on the back porch.
I had to move the potted plants inside for the winter on November 10. I always measure the cactus and succulents when I move them inside and the Mammillaria hahniana measured 2 5/8″ tall x 2 7/8″ wide. It was 1 7/8” tall x 2 3/8” wide when I brought it home on February 1, 2016.
November 29 was a nice spring-like day, so I took the cactus to the back porch for a photo shoot. I was working on a post to show the difference between the cactus in my collection.
The apex is in the center of the top of the plant. Many Mammillaria species apex is kind of concave. The axil, I think, is either the lowest part or where it starts to angle up. There are 20-30 spines in this area that appear to “unfold” as the plant grows. Be it ever so sssssllllloooowwwwllllyyyy…
Its white hair can cover the entire plant and increases in thickness and length as the plant ages. Each tubercle has 1-4 small central spines and 20-30 hair-like radial spines. Some specimens may not even have radial spines. Some Mammillaria species have latex in their tubercles and this one supposedly does…
The Mammillaria hahniana is looking its AWESOME self on July 22.
I noticed the Mammillaria hahniana had a few buds on July 4. Its wool is wet in the above photo because we had rain.
I had to move the potted plants inside for the winter on October 11 because an “F” was in the forecast. As always, I took photos of all the plants and measured the cactus and part of the succulents. The Mammillaria hahniana measured 3 1/4″ tall x 3 3/8″ wide.
I really like this plant with all this wool! I wrote a Mammillaria update on November 16 which you can view by clicking HERE.
After the “F” temperatures warmed up for a few days again. This always happens. The cactus were giving me dirty looks so I put them outside for a few days. I noticed the Mammillaria hahniana had a few buds.
As long as the cactus know it is cold outside they don’t mind being inside. Most of them are on a table in front of the sliding door, so they can tell when I go in and out.
I will continue adding more photos and information as time goes by.
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. The links take you directly to the genus and species of this plant.