Mammillaria haageana

Mammillaria haageana Pfeiff.

Kingdom	Plantae	Plants, but not fungi, lichens, or algae
Subkingdom	Tracheobionta	Vascular plants—plants with a “circulatory system” for delivering water and nutrients
Division	Magnoliophyta	Flowering plants, also known as angiosperms
Class	Magnoliopsida	Dicotyledons—plants with two initial seed leaves
Subclass	Caryophyllidae	Cacti, many other succulents, carnivorous plants, and leadworts
Order	Caryophyllales	Includes cacti, carnations, amaranths, ice plants, and many carnivorous plants
Family	Cactaceae	Succulent (water-storing) plants, often spiny
Genus	Mammillaria	From Latin mammilla, “nipple,” referring to the tubercules on members of this genus
Species	haageana

About plant names...

These cacti are native to southern Mexico.

Identification: Plants are spherical in shape, usually occurring alone, sometimes in clusters, up to 6" (15 cm) high and 4" (11 cm) wide. Spine groups on the side are arranged in a spiral pattern (instead of as vertical rows as in many other cacti), and they are closely spaced. Radial spines are in groups of 18-30, smooth, white, and bristled. They are ¹/₁₆-³/₁₆" (3-6 mm) long. Flowers range from bright purple-pink to carmine. Fruits are red.

If you look closely at the photo at right, you’ll notice that in 1979 this cactus was labelled Mammillaria elegans dealgata. When I first saw this name, I surmised that some droll botanist had perpetrated a small joke on the botanical community. What else could Mammillaria elegans possibly mean other than “nice boobs?” I was partly right. Mammillaria does refer to breasts, specifically nipples, and elegans means “elegant.” But in this context, Mammillaria refers to the tubercules on the plant surface, small raised bumps arranged in spiral patterns, the base of each group of spines. In most cacti, these are arranged as a series of vertical ribs along the stem of the cactus, but in Mammillaria, they follow the Fibonacci number sequence, a pattern that is also common elsewhere in nature.

This genus has an unusual approach to plant metabolism, absorbing CO₂ at night and re-emitting it during the day, in a way that improves photosynthesis. This is called Crassulacean acid metabolism, and it is a trait these cacti have in common with pineapples.

References:

Anderson, Edward F., The Cactus Family, Timber Press, 2001, p. 420

Rätsch, Cristian, The Encyclopedia of Psychoactive Plants: Ethnopharmacology and its Applications, Park Street Press, 1998, p. 342

Online References:

Mammillaria haageana on Mammillarias.net, a web site devoted to this genus

Mammillaria haageana on Cactus Art: the World of Cacti & Succulents

Mammillaria haageana on CactiGuide.com

Mammillaria haageana on the Mammillaria Forum (superb photos)

Mammillaria haageana on Desert-tropicals.com

Mammillaria haageana description by Thomas H. Kent, last updated 25 May 2020.

1 · 4/11/1979 · Huntington Library Cactus Gardens, San Marino, California