What is a Mammillaria ?

The genus Mammillaria is part of the botanical family Cactaceae (cacti). A genus is a group of similar plants. A family is a group of related genera. The succulent plants dispose of important sap stocks (up to 95% of the plants’ volume) and have a particular metabolism called C.A.M. (Crassulacean Acid Metabolism). Actually, this metabolism, contrarily to all other plants, is operating by night, absorbing carbonic gas and restoring oxygen during a period where temperatures are less hot in order to avoid dessication of the plants. Cacti are succulent plants, but not all succulant plants are cacti…

Mammillaria deherdtiana ssp dodsonii ML 354 photo dans la l'habitat par Michel LacosteMammillaria deherdtiana ssp dodsonii ML 354 – Michel Lacoste – Field Picture

The Cacti Family:

The Cacti Family includes over 2000 species, all native from the American continent. Some primitive species excepted, their particular identification marks are that they have no leaves, but spines born from tubercules set on the plant body. However, not every spined plant is a cactus, neither necessarily a succulent plant ! The genus Mammillaria is a member of the Cactus Family….

Mammillaria duoformis - ML 347 - Photo Michel Lacoste

Mammillaria duoformis – ML 347 –  Michel Lacoste – Field

The Genus Mammillaria:

Well, let’s talk about the Genus Mammillaria, the subject of this site. There are about 200 to 300 species depending on one of several different classifications (see the special pages). Most of them are native to Mexico, with some from the Southwest of the United States, and a few from South America and the Carribean Islands. The name Mammillaria comes from the latin word mamma, referring to the tubercules covering the plant body, and which, for a number of species, contains milky sap (latex). The Genus Mammillaria was been created in 1812 by Adrian Haworth, but the first Mammillaria (M. mammillaris) was described in 1753 by Linnaeus under the name of Cactus Mammillari. The present specialists of this genius are John Pilbeam, David Hunt, Jonas Lüthy, Michel Lacoste….

Geographical distribution map of the Genus Mammillaria :

Carte de repartition du genre Mammillaria

Carte de repartition du genre Mammillaria

A Survey of Mammillaria Characteristics:

The Body : Plants globose or globose slightly depressed or short cylindrical or clumps of short cylindrical bodies. Mammillarias are small or medium sized plants, solitary or clumping.

The Sap : is milky, watery or milky in the body and watery in the tubercules.

The Tubercules : are set in spirals ; Mammillarias never have vertical ribs. The tubercules can be angled or cylindrical more or less long and smooth. They can sometimes be a little depressed but will never be grooved between the base and the areole bearing the spines.

The Spines : are borne on the top of the tubercules (areole). They are separated in two types, the radial spines and the central spines, even if sometimes they are alike. Most often, the central spines are different. Spines can be long or short, numerous or absent, hooked or straight, hair-like, bristle-like, and wool may be present or absent in the axils at the base of the turbercle.

The flowers : usually opening during the day and born from a flowering areole set in the axils of the tubercules. The fruits, of course, come at the same place after the flowers. Offsets can also be born there. The flowers are small or medium sized and set in circles in the previous year’s growth. Form and colour are varying, usually red, yellow, white, pinkish white, pink, with midveins of another colour.

The Fruits : are most often red and rarely green or white. Usually elongated club shaped somewhat rounded, but can sometimes also be globose.

The Seeds : Brown or black depending on the species. Size varies depending on species.

Now, please go and visit the photo gallery to see the extraordinairy diversity of this genus in order to better understand what is a Mammilaria. Photos often say more than words. You also can have a look at the presented books finding perhaps more precise literature. Any question you may have referring to Mammillarias can be asked on the Forum 🙂

Mammillaria amajacensis ML 46 Photo Michel Lacoste

Mammillaria amajacensis ML 46 Photo Michel Lacoste – Field