Origin and Habitat: Sonora, Mexico.
Altitude: 0-300 metres above sea level.
Habitat and Ecology: Mammillaria booliiSN|8817]]SN|3779]] is locally common, sometimes abundant in rocky soils, across coastal mountains in thin forests together with Echinocereus scopulorumSN|21773]], Echinocereus scopulorumSN|21773]], Mammillaria swingleiSN|3779]]SN|8817]] and Ferocatus emoryi. Some parts of its habitat has been destroyed for urban development.

• Mammillaria boolii G.E.Linds.
• Bartschella boolii (G.E.Linds.) Doweld
• Chilita boolii (G.E.Linds.) Buxb.

Description: Clumping plants with soft, green or grey-green epidermis.
Stems: Up to 5 cm wide (but often more large in cultivation), with prominent rounded tubercles usually depressed globose to depressed conical when growing in habitat. While cultivated plant have (frequently) oblong offsetting stems.

Notes: Mammillaria booliiSN|3779]]SN|3779]] was once placed in the segregate genus Bartschella because of its fruit anatomy and large pink flowers located at the top of the plant. The fruit are red, thin-skinned and often break off from a basal pore rather than falling whole (like in most Mammillaria).

Bibliography: Major references and further lectures.
1) Robert T. Craig “The Mammillaria handbook: with descriptions, illustrations, and key to the species of the genus Mammillaria of the Cactaceae” E P Publishing, 1945
2) John Pilbeam “Mammillaria The Cactus File Handbook” Cirio Pub. Services, 01/Dec/1999
3) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
4) James Cullen, Sabina G. Knees, H. Suzanne Cubey "The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass" Cambridge University Press, 11/Aug/2011
5) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
6) Burquez Montijo, A. & Felger, R.S. 2013. Mammillaria boolii. In: IUCN 2013. "IUCN Red List of Threatened Species". Version 2013.2. <www.iucnredlist.org>. Downloaded on 02 April 2014.

Cultivation and Propagation: This plant is somewhat difficult to cultivate. Needs good drainage as it is rot prone.