The species of the genus
Echinocereus grow solitary or branching with prostrate to erect shoots that are spherical to cylindrical. The roots are fibrous or bulbous. The plants reach heights of growth between 1 and 60 centimeters. On the tips of the 4 to 26 ribs, which are mostly clear and only rarely resolved into humps, are the areoles, from which differently shaped spines can arise. A distinctive characteristic and likely
synapomorphy of the genus is the erumpent flowers. The floral buds develop internally and break through the epidermis of the stem. This flower morphology is likely an adaptation to protect the developing buds from low temperatures. Upon maturity, the flowers are usually brightly colored and open during the day.
Echinocereus floral color is variable because perianth color reflects pollinator specificity. Red flowers are generally associated with hummingbird pollination, while pink flowers tend to correspond to moth pollination. Their pericarp and floral tubes are studded with thorns, bristles, and sometimes wool. The scar is usually green, but sometimes white in color. The spherical to ovoid fruits are green to red and mostly thorny. They are mostly juicy and open along a longitudinal slit. The sometimes fragrant fruits contain broadly oval, black, tuberous seeds 0.8 to 2 millimeters long. ==Taxonomy==