|One plant displayed at the CSSSA Meeting, with the following notes:|
Mammillaria hahniana was first described by Werdermann in 1929. Since then I think that nearly every cacti fan who has seen one, has wanted one! It has proved to be a reasonably easy species to grow and it certainly flowers very well in cultivation. The flower colours vary from the deepest carmine through to pale pink and rare white flowered individuals also exist. A number of other species names were proposed in the 1930s and 1940s but these plants are now considered as near relatives and reduced to the rank of sub-species or variety. Mammillaria mendeliana (1931) is now relegated to Mammillaria hahniana subsp. mendeliana; Mammillaria bravoae (1945) is now Mammillaria hahniana subsp. bravoae and Mammillaria woodsii (1945) is now Mammillaria hahniana subsp. woodsii. Mammillaria saetigera may also be part of this species, although this has been disputed. There are also the named varieties, Mammillaria hahniana var. werdermanniana (1945) and Mammillaria hahniana var. giseliana (1935). Some of the variants have differing stigma and flowers colours, others have more or fewer radial and or central spines. Even plants raised from seed from the same pod may vary, especially in the length and amount of hair on the plant.
In the past, extremely hairy specimens have gone under the name Mammillaria hahniana var. superba, but this is probably more of a cultivation derived selection generated from growers preferring the hairiest plats they can find, so this name is perhaps best rendered as Mammillaria hahniana 'Superba', if it is used at all. Care should be taken not to overwater such very hairy plants, nor to get the hairs themselves wet as they can hold excessive water which can lead to rot unless the plants have the opportunity to dry out completely between waterings. This plant is one of a pair I purchased at the same time so as to have a cross pollination opportunity. I have only owned them for a few years, but I am very pleased with them so far and I am hoping to raise some more from seed in due course.