Sclerocactus Mesae-verdae

As the common name suggests, sclerocactus mesae-verdae is found mainly in and around Mesa Verde National Park in southwest Colorado, its range extending to a small area of northwest New Mexico, within the Navajo Nation. This species inhabits barren, clayish areas, plains and badlands, on soils from the Mancos or Fruitland shale formations, and is uncommon, of conservation concern. Associated plants include shadescale, mat saltbush and plains prickly pear. During prolonged dry periods the stems shrink, and the cactus can become hidden beneath the soil.

The pale green stems are up to 4 inches wide and tall. There are between 13 and 17 ribs, with shallow, inconspicuous tubercles. The pale brown or grayish radial spines number between seven and 14 per areole, spreading or slightly reflexed. Central spines are usually absent, but occasionally there is one; downwards-pointing, hooked, and similar in length to the radials, around half an inch.

Plants bloom for a few weeks only, from late April to early May. The outer tepals of the funnel-shaped flowers are red-purple, lighter at the edge, while inner tepals are creamy-yellow, less often pink. Stamens have white or pale yellow filaments and yellow anthers. Stigma lobes are pale green.