Mam’s the word: My 10 favorites

Mammillarias, or Mams for short, are arguably the most popular cactus genus among collectors across the world today.  I am sure that most collectors here in the Philippines have at least one or two Mams in their collections.  Their great diversity in spination, coloration and form, their relatively small size (which allows a collector to build a relatively large and impressive collection in a small area), their general ease of care if their basic needs are met, and their availability among plant retailers are but some of the factors that contribute to the immense popularity of Mams.

Mams contain the greatest number of species next to the genus Opuntia, with between 200 and 300 species depending on which classification scheme or which expert you follow.  While the bulk of Mams are native to Mexico, there are a few that are found in South America and even some on the Carribean islands. 

The name “Mammillaria” comes from the latin word “mammilla,” which means “nipple.”  These nipples essentially refer to the tubercles covering the plant body and which, for a number of species, contains a milky sap or latex.  What is fascinating about the symmetry and general architecture of these plants is that the tubercles are not arranged in an irregular patern, but form angled, spiraling rows crossing over each other.

The most important distinguishing feature of Mams relative to other cacti is the position of the flowers.  These do not grow from the areoles at the end of the tubercles, as in other cacti, but from the axils or the spaces between the tubercles.  Flowers come in many colors, from white to fuchsia to red.  While these flowers are generally small (with some exceptions), if one is lucky and has grown his Mam well, you may get your Mam to produce a wonderful ring of flowers around its crown.  This, I can tell you from experience, is a true sight to behold.

In terms of their care, I can tell you again from experience that there are easy-to-care for species and there are others which are a lot more difficult.  While some of my favorites belong to the easy category, most of the species that I fancy tend to be the more difficult and challenging ones.  For me, the key to success with Mams is to give them the right location, with plenty of sun and free air circulation.  I grow all my Mams in clay pots.  You can grow them successfully in a mixture of 50 percent good garden loam (sandy loam is best) and 50 percent washed river sand.  With this combination, you need to water only once a week.

Now let’s get to my first 10 favorites.  The first one I ever encountered here in Manila was M. plumosa, the feather cactus, because of its feather-like spines that engulf the entire body into a while ball.  I remember buying my first plant several decades ago for the grand sum of P50  ( a lot of money in those days!).  Unfortunately, the plant was not a healthy one to start with (its color was a faded gray instead of the clean white in healthy specimens), but being a neophyte, I couldn’t tell the difference.  Today, M. plumosa is readily available across the country.  It seems to grow well even in locations that are not quite ideal, and will flower in shades of whitish yellow to whitish pink beginning in November till early February.  This easy-to-care for Mam is also, for me, one of the most beautiful, whether it is growing singly or in a clump of heads.

A second favorite is also another easy-to-grow Mam, M. camptotricha v. delapostella, a beautiful variant of the bird’s nest Mam, named for the spiral arrangement of its spines.  This is one of the few “green” Mams that I like.  While it can survive in less-than-ideal light conditions, it is best grown in full sunlight to get stronger, more colorful spination and a more natural growth.

The rest of the Mams in my first 10 are the rarer and more difficult to grow.  Because of their spination and distinctive appearance, these plants are among the most valued and sought-after Mams in the world.  I have managed to kill a number of these in the less-than-ideal conditions in my Makati home, but the plants are now doing very well in their new location in Tagaytay.  Probably the easiest one to grow among this bunch is M. humboldtii.  These plants eventually produce a mass of heads and beautiful clumps in the process.  The contrast of the fuchsia flowers to the overall white bodies is an amazing sight to behold.  M. theresae has a very interesting body configuration, and its flowers are huge and spectacular.

M. hernandezii is a plant I have killed several times, due mainly to overwatering when I used to grow these in plastic pots.  I have finally learned from all my previous failures, and don’t foresee any further problems with this species.  M. crucigera is another beautiful plant that is easier to grow than M. hernandezii, and more tolerant (up to a point) of more water.  But it takes a lot of time and patience to grow a nice clump of heads.  And for me, it is these mature clumps that depict this species at its best.

Another Mam which troubled me in the past is M. solisioides.  This plant from Oaxaca and Puebla in Mexico has beautiful off-white pectinate spines.  Slow growing, this plant is very rot-prone and temperamental.  It has a fairly large tap root and should be kept in a deep pot with very good drainage.  M. herrerae v. albiflora from Guanajuato, Mexico, is another of the very beautiful spined white Mams close to my heart.  Unlike the typical species, this plant grows more columnar and produces spectacular white flowers.  M. lenta is another of the white Mams that produce very tight, white bristly spines all over its body.  It produces white flowers with a pinkish mid-stripe.  With good care, nice multi-headed clumps will be produced.

 My favorite of these difficult Mams (in fact, my favorite Mam, period!) is M. luethyi.  I just love its dark brownish purple tubercles, its small, squat growth and its overall appearance.  The existence of this Mam has been known for some time, but only fairly recently has it entered into cultivation.  It was rediscovered in habitat in Northern Coahuila, Mexico, in 1996 by George Hinton and Jonas Luethy, after whom the species is named.  It produces beautiful huge flowers (similar to that of M. theresae), but this plant remains distinctive even when not in flower.  Because it is extremely rot-sensitive from overwatering, most of the plants in cultivation today are grafted.