WILDFLOWERS OF NEW MEXICO

Most of this 2 3/4–6-inch wide, flat, hemispheric cactus is underground. Only the top 3/4–2 inches extend above the surface. Spiral rows of 3/8–5/8-inch long tubercles, or nipples, cover the stem top. Note the milky stem juice.

FLOWER: March–April. A circle of 3/4–1 1/2-inch wide and long flowers grow in a circle below the flattened apex. Pointed, creamy to white petals (tepals) usually have a pinkish mid-stripe. Club-shaped fruits mature bright red and 3/8–1 3/8-inch long (10–35 mm) and often remain on the cactus through the next flowering season.

SPINES: The areole on each nipple of variety heyderi (widespread) has 13–17 thin, needle-like radial spines 1/4–1/2-inch long (6–12 mm), and 1 central spine 3/16–1/2-inch long (5–12 mm), stiff and straight without a hooked end; var. macdougalii (Boothill) has 10–12 radial spines.

HABITAT: Dry rocky, sandy soils of desert scrub, limestone hills.

ELEVATION: 6,000–7,000 feet.

RANGE: AZ, CO, NM, OK, TX.

SIMILAR SPECIES: In much the same range, Little Nipple Cactus, M. heyderi var. meiacantha, considered a separate species by some, is distinctive with 5–7 thicker radial spines and pinkish to dull-red fruit.

NM COUNTIES: In south and central NM in mid-elevation arid habitats: Bernalillo, Chaves, Colfax, Dona Ana, Eddy, Grant, Guadalupe, Hidalgo, Lincoln,  Luna, Otero, San Miguel, Sierra, Socorro, Torrance.