Growth Habits: Solitary or clustering stems. The tubercles are long and very dark green, almost black looking on a well kept plant. The areoles are white with many white, soft radial spines giving a 'spider-like' appearance. In a well grown plant the areoles appear to go round the plant in a whorl and are very close and tightly packed together at the apex of the plant. This is a small plant perhaps only half to three quarters of an inch in diamater [1.5 to 2cms.], but one that will offset quite freely when established. Plants in the wild are almost buried in shallow but very free draining limestone.
Scientific name: Mammillaria luethyi
Synonyms:
Etymology: Mammillaria From the Latin word mammilla, meaning nipple or teat.
Luethyi: Named in honour of the co-finder, Jonas Luethyi
Origin: The plant can be located at the north of the state of Coahuila, Mexico, in a mountainous area (fluoride mines). The land is pretty inhospitable.
Light: The plant requires full sun to light shade. If the plant is not getting enough sun the tubercles become wide spaced and the plant looks insipid.
Compost: A very free draining compost is required as these plants have a tendency to rot at the roots. Whatever you use in your compost to 'open it up' i.e. chicken grit, perlite, pumice etc. add at least another 10%
Water: Careful watering is required in summer and little or no water should be given in the winter, depending on your location and how warm the plant is kept during the winter months.
Flower: The flower is large for a Mammillaria and the plant is also one of the first of the Mammillaria to flower. A description by me would not do justice to the flower, suffice to say the above photograph is a reasonably good representation of it.
Min. temp: Requires a minimum temperature of 45-50°f. (8-10°c.)
Cultivation: As you will have gathered by now, this plant is not the easiest cactus to keep healthy and looking its best, but with a little care it can be done quite successfully and is well worth the extra effort. It is quite a unique looking Mammillaria and the large flowers are a real bonus in a Genus that is not known for the beauty of its flowers (I apologise unreservedly to all fans of the Mammillaria genus, that have been upset by this statement).
Comments: This really is a beautiful Mammillaria that is becoming more widely available. Many of the plants that are for sale are grafted, but they should not be discounted because of this. The plant is much easier to keep on a grafted stock and will grow and flower much more quickly. Also watering is not as critical on the grafted plant. This plant in full flower is a sight to behold and if you are lucky you should get two or maybe even three flushes of blooms.