Soil

One of the largest genera
Species ranger in size from an inch to a yard

Soft and fuzzy appearing, low clustering small barrels with cream-colored flowers.

Usually solitary. Cylindrical to 12″h. Short pyramidal tubercles, not woolly. Crown of small bright pink flowers.

Small globose with variable flowers, lots of bristles

3-4″ round stems form large clusters. Circular clusters of deep pink flowers are borne on the upper surface in spring and summer. Hooked spines, downy white hairs.

Usually solitary, some clumps; to 10″h.; woolly between short central spines

4″. Dense clusters of deep green globose stems. Wild spines, creamy flowers.

Long stems, 1″ diameter, clumping; tight star-shape spines. Small cream-colored flowers form a crown around the tips of the stems.

Cultivar with red spines. Small cream-colored flowers form a crown around the tips of the stems.

Lots of short golden stems, tightly clumping. Small cream-colored flowers form a crown around the tips of the stems.

Large clumps of 3″d. x 7-8″ long stems.

Small, 4″ cylindrical stems, will form larger multistem clusters. Light pink flowers.

Stems cylindrical to 4″ diameter. Wooly between tubercules. Sometimes has longer radial spines. Species is variable, and there are 4 subspecies. Flowers rose-pink to red. Will form large clumps over time. Frost resistant if dry in winter.

Small solitary green globular plant to 2″

Very cold hardy. Small ball cactus to 5″d.

Low dense clusters get covered with fine white hairs

Mini grey-green globular plant covered w/soft white spines. Readily clumping

M. standleyi

Slow to form clumps, 3 to 4 ft across. Globose stems to 6″. Prominent conical tubercles. Yellowish flowers.

8″d. Clumping w/prominent tubercles, some axil wool