Mammillaria

The genus Mammillaria is one of the largest in the cactus family (Cactaceae), with currently 171 known species and varieties recognized. Most of the mammillarias are native to Mexico, but some come from the southwest USA, the Caribbean, Colombia, Venezuela, Guatemala and Honduras.

The first was described by Carolus Linnaeus as Cactus mammillaris in 1753, deriving name from Latin mammilla, "nipple", referring to the tubercles that are one of the plant's specific features. In 1812, the cactus specialist Adrian Haworth described the genus Mammillaria to contain this and related species. Numerous species are commonly known as nipple cactus, fishhook cactus or pincushion though such terms may also be used for related taxa, namely Escobaria

Mammillarias have extremely variable spination from species to species, and attractive flowers, making them specifically attractive for cactus hobbyists. Most mammillarias plants are considered easy to cultivate, though some species are among the hardest cacti to grow. Several taxa are threatened with extinction at least in the wild, due to habitat destruction and especially overcollecting for the pot plant trade. Cactus fanciers can assist conservation of these rare plants by choosing nursery-bred specimens (wild-collected ones are illegal to possess for the rarest species anyways). Besides helping to preserve rare plants, one can gain experience in growing and breeding cacti in general with nursery-bred rare mammillarias: several mammillarias are quite easy (for cacti) to grow from seeds. One such species, popular and widely available from nursery stock but Endangered in the wild, is Mammillaria zeilmanniana.

Description

The distinctive feature of the genus is the specific development of an areole, that is split into two clearly separated parts, one occurring at the tubercle's apex, the other at its base. The apex part is spine bearing, and the base part is always spineless, but usually bearing some bristles or wool. The base part of the areole bears the flowers and fruits, and is a branching point. The apex part of the areole does not carry flowers, but in certain conditions can function as a branching point as well.

The plants are usually small, globose to elongated, the stems from 1 cm to 20 cm in diameter and from 1 cm to 40 cm tall, clearly tuberculate, solitary to clumping forming mounds of up to 100 heads and possess radial symmetry. Tubercles can be conical, cylindrical, pyramidal or round. The roots are fibrous, fleshy or tuberous. The flowers are funnel-shaped and range from 7 mm to 40 mm and more in length and in diameter, from white and greenish to yellow, pink and red in color, often with a darker mid-stripe; the reddish hues are due to betalain pigments as usual for Caryophyllales. The fruit is berry-like, club-shaped or elongated, usually red but sometimes white, yellow or green. Some species have the fruit embedded into the plant body. The seeds are black or brown, from 1 to 3 mm in size.

Systematics

The large and diverse genus Mammillaria has seen multiple attempts to subdivide the species in it into smaller groups within the genus or attempts to split it to multiple genera for better understanding of the plants' relationship. Early classifications were performed by Pfeiffer (1837), Salm-Dick (1845) and Engelmann (1856). The genus Mammillaria included members of some modern genera like Coryphantha and Ariocarpus at that time. Classifications by Schumann (1898), Britton and Rose (1923), Berger (1929) Buxbaum (1951-56) and Moran (1953) followed, splitting the genus in parts and combining it back together again.

Later classification was performed by the cactus specialists Hunt, Reppenhagen and Luthy, with a lot of work focusing on searching the meanings and value of the original plant descriptions, synchronizing them with modern taxonomic requirements and studying the morphology of plants and seeds, as well as ecological aspects of the genus. These works helped to expand the understanding of Mammillaria taxa.

Currently the classification of Mammillaria is in a state where few newly discovered species are likely, though some new species may yet be found when the chaos of names created earlier by commercial plant collectors is sorted out. Many names that were introduced for plants barely differentiated by a shade of flower color or variation in spination were eliminated in attempt to make the use of names consistent with the rest of the botanical world. The number of taxa, which at one time numbered above 500, is now below 200. Some genera (Dolichothele, Mammillopsis, Krainzia and others) have been merged back into Mammillaria, and others like Coryphantha, Escobaria and Mammilloydia were confirmed as separate.

Intense studies of DNA of the genus are being conducted, with preliminary results published for over a hundred taxa, and this promising approach might soon end the arguments. Based on DNA research results, the genus does not seem to be monophyletic and is likely to be split into two large genera, one of them possibly including certain species of other closely related genera like Coryphantha, Ortegocactus and Neolloydia.

Selected species

As noted above, some might not belong into this genus. Mammillaria albicoma
Mammillaria albiflora
Mammillaria albilanata
Mammillaria angelensis
Mammillaria anniana
Mammillaria aureilanata
Mammillaria backegergiana
Mammillaria barbata – Green Fishhook Cactus
Mammillaria baumii
Mammillaria berkiana
Mammillaria blossfeldiana
Mammillaria bocasana
Mammillaria bocasana f. multilanata – Powder-puff Pincushion
Mammillaria bocasana ssp. eschauzieri – Eschauzier's Pincushion
Mammillaria bombycina – Silken Pincushion
Mammillaria boolii
Mammillaria brachytrichion
Mammillaria candida
Mammillaria carmenae
Mammillaria carnea
Mammillaria celsiana
Mammillaria centricirrha
Mammillaria columbiana
Mammillaria compressa – Mother of Hundreds
Mammillaria crinita – Rose Pincushion Cactus
Mammillaria crocidata
Mammillaria crucigera
Mammillaria dawsonii
Mammillaria decipiens
Mammillaria dioica – Strawberry Cactus, California Fishhook Cactus
Mammillaria discolor
Mammillaria dixanthocentron
Mammillaria duwei
Mammillaria elongata – Ladyfinger Cactus
Mammillaria fraileana
Mammillaria gasseriana
Mammillaria geminispina – Twin-spined Cactus
Mammillaria geminispina f. cristate – Crested Twin-spined Cactus
Mammillaria gigantea
Mammillaria glassii
Mammillaria glochidiata – extinct in the wild
Mammillaria goodridgei
Mammillaria goodridgei var. goodridgei
Mammillaria goodridgei var. rectispina
Mammillaria grahamii – Arizona Fishhook Cactus
Mammillaria grahamii var. oliviae – Pitahayita
Mammillaria grusonii
Mammillaria guelzowiana
Mammillaria guerreronis
Mammillaria guillauminiana – extinct in the wild
Mammillaria haageana
Mammillaria hahniana – Old Lady Cactus
Mammillaria hernandezii
Mammillaria herrerae
Mammillaria heyderi
Mammillaria huitzilopochtli
Mammillaria humboldtii
Mammillaria johnstonii
Mammillaria karwinskiana – Royal Cross Mammillaria
Mammillaria klissingiana
Mammillaria kraehenbuehlii
Mammillaria krameri
Mammillaria lasiacantha – Golf-ball Pincushion Cactus
Mammillaria lauii
Mammillaria lenta
Mammillaria longiflora
Mammillaria longimamma – Finger Cactus
Mammillaria longimamma var. sphaerica – Longimamma Nipple Cactus
Mammillaria luethyi
Mammillaria magnifica
Mammillaria magnihahha
Mammillaria mainiae – Counterclockwise Pincushion
Mammillaria magnimamma – Mexican Pincushion
Mammillaria marcosii
Mammillaria marksiana – Cabeza de Viejo
Mammillaria mathildae
Mammillaria matudae
Mammillaria melaleuca
Mammillaria melanocentra
Mammillaria mercadensis
Mammillaria microhelia
Mammillaria microthele
Mammillaria muehlenpfordtii
Mammillaria multidigitata
Mammillaria mystax
Mammillaria neopalmeri
Mammillaria nivosa – Woolly Nipple Cactus
Mammillaria nunezii
Mammillaria obconella
Mammillaria painteri
Mammillaria parkinsonii – Owl's Eyes
Mammillaria pectinifera – Conchilinque
Mammillaria pennispinosa
Mammillaria perbella
Mammillaria perezdelarosae
Mammillaria petrophila
Mammillaria petterssonii
Mammillaria plumosa – Feather Cactus
Mammillaria polythele
Mammillaria pondii
Mammillaria poselgeri
Mammillaria pottsii – Rattail Cactus
Mammillaria prolifera – Texas Nipple Cactus
Mammillaria rekoi
Mammillaria rettigiana
Mammillaria rhodantha – Rainbow Pincushion
Mammillaria saboae
Mammillaria sanchez-mejoradae
Mammillaria sartorii
Mammillaria schiedeana
Mammillaria schumannii
Mammillaria schwarzii
Mammillaria sempervivi
Mammillaria senilis - a.k.a. Cochemia senilis, a.k.a. Mamillopsis senilis, a.k.a. Mamillopsis diguetii, a.k.a. Mammillaria diguetii
Mammillaria sheldonii – Sheldon's Pincushion
Mammillaria sonorensis
Mammillaria spinosissima – Red-headed Irishman
Mammillaria spinosissima ssp. pilcayensis – Bristle Brush Cactus
Mammillaria standleyi
Mammillaria stella-de-tacubaya
Mammillaria supertexta
Mammillaria surculosa
Mammillaria tetrancistra – California Pincushion
Mammillaria theresae
Mammillaria thornberi – Clustered Fishhook Pincushion
Mammillaria uncinata
Mammillaria vetula
Mammillaria voburnensis
Mammillaria weingartiana
Mammillaria wiesingeri
Mammillaria winterae
Mammillaria wrightii – Brown Pincushion
Mammillaria wrightii ssp. wilcoxii – Wilcox's Nipple Cactus
Mammillaria zeilmanniana

Translation

The word "Mammillaria" occurs as such in the following languages: English, Spanish, French, Croatian, Italian, Dutch, Portuguese.

Translation(s) in other languages: Catalan: Mamil·lària, Czech: Mamilárie, Danish: Vortekaktus, German: Warzenkakteen, Georgian: მამილარია, Lithuanian: Mamiliarija, Polish: Mamilaria, Russian: Маммиллярия, Finnish: Syyläkaktukset, Swedish: Vårtkaktussläktet.