Mammillaria

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From Wikipedia, the free encyclopedia The genus Mammillaria is one of the largest in the cactus family Cactaceae, with currently 171 known species and varieties recognized. The first was described by Carolus Linnaeus as Cactus mammillaris in 1753, deriving name from Latin mammilla = nipple, referring to the tubercules 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.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 tubercule'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 posses radial symmetry. Tubercules 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 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. Mammillarias have extremely variable spination from species to species, and attractive flowers, making them specifically attractive for cactus hobbyists. Mammillaria plants are considered easy in cultivation, though some species are among the hardest cacti to grow.Most of the mammillarias are native to Mexico, but some come from the southwest USA, the Caribbean, Colombia, Venezuela, Guatemala and Honduras.