Origin and Habitat: Coahuila, Mexico.
Altitude: 1000 to 1230 metres above sea level.
Habitat: This plant is a mud crack dweller, growing almost sunken in cracks in the dry lake at the Laguna de Viesca.

• Mammillaria coahuilensis (Boed.) R.Moran
• Mammillaria heyderi subs. coahuilensis (Boed.) Lüthy
• Porfiria coahuilensis Boed.

• Mammillaria coahuilensis (Boed.) R.Moran
• Mammillaria heyderi subs. coahuilensis (Boed.) Lüthy
• Porfiria coahuilensis Boed.
• Mammillaria coahuilensis var. albiflora (Boed.) Boom
• Porfiria coahuilensis var. albiflora Boed.
• Mammillaria schwartzii (Frič) Backeb.
• Haagea schwarzii Frič
• Neomammillaria schwarzii Rose & Frič
• Porfiria schwarzii (Frič) K.Crkal

• Mammillaria coahuilensis subs. albiarmata (Boed.) D.R.Hunt
• Mammillaria albiarmata Boed.
• Mammillaria coahuilensis var. albiarmata (Boed.) B.Hofmann

Description: Mammillaria coahuilensisSN|15105]]SN|15100]], also known as Mammillaria schwartziiSN|15100]]SN|15105]], is a small geophyte cactus, with a heavy tap root that may exceed the size of the plant above soil level.
Stems: Solitary flattened globose, blue-green, up to 5 cm high and in diameter.
Spines: About 12-16, thin, bristle-like radial spines, slightly pubescent with darker tips, up to 6 mm long. Central spine: not present or 1, straight, needle-like, darker, up to 6 mm long.
Flowers: White with pinkish midveins, very early in the season, February/March.
Fruits: Red clavate.

Bibliography: Major references and further lectures
1) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
2) 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
2) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
3) John Pilbeam “Mammillaria: the cactus file handbook” Cirio Publishing Services Ltd Dec/30,/1999

Cultivation and Propagation: This species has few special demands. Whatever view one adopts, it is worth a place in every Mammillaria collection. The only problem is that it is very slow growing, a plant for patient growers.
Like all thick-rooted species, it requires careful watering (rot sensitive), and patience to match its slow growth. During the winter rest, the plant may pull near the surface of the potting mix.
Propagation: Direct sow after last frost. (it usually doesn't produces offsets).