This petit, rounded, 2 1/2-inch tall, 1 3/4-inch-wide cactus blends in perfectly in rocky scrabble of limestone hills. A rough covering of overlapping, grayish spines obscures the solitary or clumped stems. Note the tiny, solid pinkish-whitish flowers and erect, bright-red, club-shaped fruits.

FLOWER: Early spring (March). Clusters of 1–8 small flowers, 1/8–3/16-inch wide (3–4.6 mm), at the stem apex in an upswept tuft of spines, 5–8 solid pink to whitish petal-like tepals (without reddish mid-stripes), each tepal 1/8-inch long (3.5 mm), the smallest flower of any cacti in NM; stamens have pink to creamy anthers, stigma lobes white. Clusters of erect, red fruit, 3/8–1/2-inch long and thin (9–12 mm), crowd the top of the stems. Flowers close by mid-afternoon.

SPINES: Areoles have 20–35 flat-lying spines that form a tight network around the stem; whitish-gray radial spines, 1/16–1/4–inch long (2–6 mm); spine clusters obscure the stem and give the plant a lacy appearance, longer spines protrude around a rounded stem apex, no central spines present.

HABITAT: Rocky, limestone hills; desert grasslands and scrub.

ELEVATION: 3,000–5,000 feet.

RANGE: AZ, NM, TX.

SIMILAR SPECIES: Golf Ball Cactus, Mammillaria lasiacantha, in much the same range and habitat, has 40–60 radial spines in 3/8-inch wide (10 mm) clusters per areole, flat-lying with no central spines, and whitish flowers with red median stripes that bloom around the edge of the apex.

NM COUNTIES: South-central half of NM in low-elevation, rocky, arid habitats: Chaves, Dona Ana, Eddy, Hidalgo, Lincoln, Otero, Sandoval, Sierra, Socorro.