Hippeastrum is a genus of about 90 species, and over 600 hybrids and cultivars, of perennial, herbaceous and bulbous plants, native to tropical and subtropical regions of the Americas, from Mexico south to Argentina and on some islands in the Caribbean. The majority have large, fleshy bulbs—usually about the size of a softball—and tall, broad, strap-like leaves that are (generally) evergreen, and large red or purple flowers. Numerous colors and cultivars have been created over the past hundred years.

In botany, a bulb is a short underground stem with fleshy leaves or leaf bases that function as food storage organs during dormancy. In gardening, plants with other kinds of storage organ are also called ornamental bulbous plants or just bulbs.