Adenium obesum, also called the desert rose, impala lily, mock azalea and sabi star, is a thornless succulent with thick stems or trunks that taper gradually upward. The plants range in size from shrubs to small trees and bear showy masses of blossoms that are considered the most spectacular of all succulents.
Adenium obsum is in the same botanical family as the periwinkle, orleander, spiny Madagascar palm and the plumeria. The plants originated in African areas with with dry climates and extended dry seasons, thus one of its names, impala lily because of its colorful blossoms.
Description of Flowers
Adenium obesum flowers are tubular with flared lips, ranging in color from pink and white through a deep purplish red. The numerous cultivars of Adenium obseum produce flowers of different shapes, sizes and colors. Not all cultivars have fragrant blooms.
Temperature and Blooming
Adenium obesum stores water in its large, tuberous roots, enabling it to survive in dry climates and endure drought. If kept warm and given enough water Adenium obseum is semi-evergreen, dropping its leaves and going dormant a few weeks in the spring and early summer. The plants flower more in the sun and during drier weather. Adenium obesum will not do well in the shade; if it is kept in the shade during the growing season, it will not produce blossoms.
When they get enough heat and water, some Adenium cultivars flower for two to four months. Other varieties bloom nearly all year around. Most plants stop growing and flowering when temperatures exceed 100 degrees F. Cold or drought can make them go dormant for several months. Improved cultivars bloom almost continuously if given proper care.
Blossoms When Container Bound
Pink to red flowers can rise from the stems of plants from 6 to 8 inches high and two to three years old. They can easily be grown from plants and can yield blossoms when grown as bonsai.
Blossoms of Cultivars
Adenium obesium gives white flowers edged with pink or deep red. Adenium boehmianum from northwestern Namibia and southern Angloa yields pale, pinkish-purple flowers. Adenium multiflorum bears bright red flowers with white interiors. Adenium swazicum gives pale pink to deep purple flowers.
Adeniums have a toxic sap that is used in Africa to make poisoned arrows. Be careful when you handle or prune them. Do not get sap in your eyes. If you get adenium sap on your skin, wash promptly.