What are Adenium Succulents?
Adenium succulents are succulents and evergreen plants with a branching aerial section covered with lustrous, oval, bright green leaves.
The Adenium plant, best known as Desert Roses, belongs to a genus of flowering tropical plants from the Arabian Peninsula, but they are also found in Africa and Asia.
They are part of the dogbane family, Apocynaceae.
It contains over 150 species and is the only genus in the family to have both trees and shrubs as well as succulent plants.
The name Adenium is derived from the Arabic name Aden, named after the area where they were discovered.
It has been reported that this variety of plant was first cultivated by French botanist Charles Lemaire in Madagascar in 1883.
Some of the most popular Adenium species include Adenium arabicum, Adenium obesum, and Adenium somalense.
Adenium succulents are popular because they can survive in harsh conditions.
They grow well in dry and hot environments and need little water for their survival.
However, they can generally grow in a wide range of temperatures and different soil types too.
The plants are often found in Africa, Asia, and Australia. They have thick, fleshy stems that store water in a spongy tissue called a pith.
The leaves of succulents are usually thick and succulent with a waxy surface.
The flowers of Adenium varieties may be pink, white, or red, with darker outside edges.
The blooms alone, together with the shine of the leaves, make it a popular plant for ornamental purposes, especially for home decor.
It is a slow grower; on average, it takes over 3-5 years to grow to maturity.
However, Adenium blooms for a long time, from spring until the end of summer. Sometimes you see the blooms first, then the leaves.
For other types of succulents, read further:
Types of Adenium Succulents
Adenium obesum
Adenium obesum, the most common desert rose plant, is a toxic blooming shrub native to subtropical and tropical eastern Africa and the Arabian Peninsula.
Some of the more common names are Abi Star, Kudu, Fake Azalea, and, as mentioned previously, Desert Rose.
This desert rose is a succulent evergreen or drought-tolerant shrub with leaves that fall off during cold periods.
The blossoms are usually crimson or pink, with a faint tint going outward from the middle of the plant.
Adenium obesum produces seeds with two pappuses (i.e., there is a tuft of hair at each end of the seeds).
This is a warm-season ornamental plant that is often cultivated as a bonsai due to its small size.
It is best to frequently water the desert roses during the summer, especially if they are in full sun conditions.
When the temperature falls below 55 degrees Fahrenheit, watering should be drastically reduced.
Due to the less direct sunlight throughout the winter months, they must be kept indoors as container plants.
Adenium obesum should be planted in terra-cotta pots with drainage holes, which enable excess water to drain out quickly.
When repotting, use a cactus or succulent mix and avoid using a huge pot. The desert rose is often planted in pots to allow for simple transportation.
Desert roses may be cultivated in containers, gardens, and landscapes. Because it thrives in warm conditions, the Desert Rose is a common plant indoors in many parts of the United States (except USDA hardiness zones 11 and 12).
Summer is the best time to see the plants in full bloom, when their beautiful pink, rose, or red flowers, as well as their bright green foliage, burst into full color.
Several hybrids have been created. The “Adenium Hybrid” is a cross between Adenium obesum seeds and Adenium Arabicum seeds.
This hybrid, like the others, requires full sun exposure. This hybrid’s leaves will drop in the winter and reappear in the spring and summer.
The Hybrid Obesum, as a result of cross-pollination, has many additional hues, such as white, purple, and red.
Adenium multiflorum
Adenium multiflorum is a species of Adenium desert rose that is a succulent tree.
Some consider Adenium multiflorum to be a subspecies or variety of Adenium obesum.
It mainly grows in central and eastern South Africa and is considered one of the most beautiful desert roses.
It grows in arid forests and grasslands and may be deciduous or evergreen.
The height of Adenium multiflorum may vary from half a foot to 10 feet tall (half a meter and 3 meters).
Adenium multiflorum, often known as the Impala Lily, can endure protracted periods of drought as it grows well in full sun and well-drained potting soil.
It can thrive in USDA hardiness zones 10 and 11, and may be cultivated as a bonsai plant, which is what most gardeners have.
A typical five-petaled flower has red or pink petals, but they can also be white or bi-colored.
As for its leaves, they are simple, smooth-edged leaves that are often alternately structured and oppositely orientated.
A common pest is the tobacco whitefly, which wreaks havoc on the plant.
Fun fact: cardiac glycosides are found in the latex of Adenium multiflorum. This latex may be used to make archery poison and fish stunners.
Adenium arabicum
Adenium arabicum is a desert rose that is often grown as a bonsai, with shiny leaves, a nice growth pattern or shape, and blossoming flowers.
Some of the more common names include elephant’s foot and Adan bush.
It is an attractive succulent, growing up to 15 feet (5 meters) tall. It almost looks like an Adenium obesum.
Adenium arabicum is mainly found in Yemen and Saudi Arabia. The leaves of this species have a huge surface area that seems to be made of leather.
The shape of the leaves is spherical and plump. With a definite root stalk that has very little differentiation between the trunk and branches.
Bark may vary in hue, from purple to dark brown. The stems and petioles have a characteristic crimson coloring, and the seed pods contain large seeds.
The flower blossoms range from pink to reddish-pink and boom from the spring through the summer.
They are tubular, appear for two to three days, and may emerge before the leaves.
As for caring for the Adenium arabicum, make sure that there is no standing water in the soil when watering it.
A good rule of thumb is to make sure your soil is well-drained and let it dry fully before watering again.
If you’re going to plant adeniums in the ground, plant them so that the rainwater can drain away after any heavy storm.
Adenium socotranum
Adenium socotranum is a bizarre-looking desert rose species. These Adenium plants resemble trees more than any other type of plant.
Some of the more common names for this plant include Socotra rose, Socotra desert rose, Socotra island rose, and Socotra bottle tree.
Socotranum was named after the Indian Ocean island of Socotra.
Mature plants in the wild are typically massive pachycaul plants (meaning a tree with few branches and a disproportionately large trunk for its height).
It has a few short, sparsely-vegetated branches protruding from its top.
Socotra roses typically lose the majority of their leaves in the early spring, but some remain throughout the year.
Socotra desert roses can live for hundreds of years in the wild. The species’ adaptations have been compelled by the harsh climate.
The plant’s natural form changes constantly due to the island’s varied topography and climate.
The plant’s globular or columnar shape, which has a low surface area to volume ratio, reduces water transpiration.
If it doesn’t rain or fog for an extended period of time, the plant’s fat caudex can hold a lot of water.
Adenium socotranum produces a toxic sap that discourages predation.
A sap cycling mechanism in the fat caudex prevents overheating, and sun radiation is reflected by micro-anatomical epidermal protrusions.
Adenium boehmianum
Adenium boehmianum, a deadly and poisonous desert rose succulent, is native to Namibia’s northern and southern dry regions.
While resembling a small tree, it can reach a height of 8 feet and a width of 2 feet.
This plant’s broad, club-shaped leaves are the largest of all adeniums, reaching up to 6 inches in length.
Each branch has a three-month-long spiral of lustrous grayish green foliage.
These leaves, spiraling and crowded at the branch tips, are only in bloom for three months of the year.
This dormant and slow-growing plant awakens in the winter when it is most active.
A plant will only produce flowers for a few weeks during the winter growing season.
In its native habitat, seeds are released through the longitudinal opening in the oblong fruit. Because of their lateral tufts, the seeds are dispersed by the wind.
The San people (or Bushmen) from the southern regions of Africa, boil the root sap and latex to make arrow poison, which has significant cardiotoxic effects when used to hunt large prey.
The most difficult aspect of caring for a bushman’s poison arrow plant is ensuring that it receives adequate water.
Submerging this desert rose should be avoided because it may force it to enter its dormant rest period sooner than expected.
Overwatering causes root rot, which can quickly kill this plant. Use the soak-and-dry method only after the well-drained soil has dried to a few inches below the surface.
Saturate the soil, then allow it to dry partway down.
If you have your plants outside, water them twice a month in the spring and mid-summer and once a month the rest of the year.
Fertilizer should have a high phosphate and potassium content but a low nitrogen content.
Adenium crispum
Adenium crispum can be mainly found on a sandbar off the coast of southern Somalia.
A unique feature of this plant is that the caudex (i.e., the stem root system) is an underground structure like most plants, but it is concentrated at the top, above soil level.
During its growing phase, it has the ability to re-root from the bottom. The height of the stems is approximately one foot.
The quilled petals of the Adenium crispum are white with red lines extending from the throat to the edges.
Its small blooms are one of its most distinguishable features.
Flowers with variegated red and white petals are the most common, but sometimes solid red petals bloom.
Adenium crispum plants are extremely sensitive to cold temperatures. In addition, they are also sensitive to humidity and heat.
For these reasons, and despite its beautiful flowers and compact size, it is not commonly grown by gardeners for these reasons.
Adenium swazicum
An endangered desert rose variety, Adenium swazicum, is a flowering plant native to South Africa.
It’s a good rockery plant as well as a medicinal herb that is good for indoors. It is a short succulent that has a partially hidden broad and round base stem.
Adenium swazicum can grow up to two to three feet tall (60 to 90 cm).
There are numerous greenish-to-greyish branches that can reach up to six inches (15 cm) in length. It is a deciduous shrub that goes dormant in the winter months.
From late summer to autumn, the small dwarf shrub blooms lily-like, pink flowers on thick and tall branches.
Because the flower tube is much more compact and tighter as compared to other plants, natural pollination is rather difficult for Adenium swazicum.
Adenium swazicum is considered a critically endangered plant. These desert rose plants are cleared out to make room for sugar cane plantations.
Further, the sugar cane that is grown creates salty and acidic soil that few plants can survive.
Additionally, traditional healers and horticulturists harvest the entire plant in the wild and use it for therapeutic purposes.
When an Adenium swazicum is harvested, there is no propagation or replanting to prolong its existence.
According to research studies, at the rate of deforestation and usage of Adenium swazicum, the native plants will be reduced by 80 percent over the next several decades.
FAQ
Is Adenium an indoor plant?
The desert rose plant, Adenium obesum, is an indoor succulent with a broad range of two to three-inch blooms. This Arabian succulent is a great option for the intrepid gardener since it is easy to cultivate and looks great in warm areas or within container gardens.
Do Adenium succulents need direct sunlight?
Adeniums grow in full sun in their natural environment, so they need enough light to flourish. Direct sunshine is desirable, particularly during the summer months when they are in their active development period.
What is the best soil for Adenium?
Plant these Adenium succulents in soil that is well-drained but retains some water. Adding some soil amendments like perlite and peat moss would help retain some moisture. To reduce the possibility of root rot, only water when the soil has dried out. Never leave these succulent plants in water. The plants should get enough sunshine.
Is Adenium poisonous?
Adenium, also known as Desert Rose, is on the list of plants that are highly hazardous to people, dogs, cats, and horses. The plant is known to possess strong poisons that, if consumed in sufficient quantities, may be fatal.
References
- Van der Walt, K. & Witkowski, E. (2017). Seed viability, germination and seedling emergence of the critically endangered stem succulent, Adenium swazicum, in South Africa. South African Journal of Botany, Volume 109, Pages 237-245. URL: https://www.sciencedirect.com/science/article/pii/S0254629916337875
- Van der Walt, K. (2016). Population biology and ecology of Adenium swazicum. 10.13140/RG.2.1.4557.0169. URL: https://www.researchgate.net/publication/303858018_Population_biology_and_ecology_of_Adenium_swazicum
- Bulannga, M. (2017). Adenium swazicum Stapf. South Africa National Biodiversity Institute website. URL: http://pza.sanbi.org/adenium-swazicum
- Chamberland, M. (2021). Growing Adeniums in Southern Arizona. Publication AZ1953-2021, University of Arizona Maricopa County Cooperative Extension. URL: https://extension.arizona.edu/pubs/growing-adeniums-southern-arizona
- American Society for the Prevention of Cruelty to Animals. (n.d.). Desert Rose. Pet Care Animal Poison Control Toxic and Non-toxic Plants, American Society for the Prevention of Cruelty to Animals (ASPCA). URL: https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/desert-rose
- About/metions: Adenium, succulents
Lindsey Hyland grew up in Arizona where she studied at the University of Arizona’s Controlled Environment Agriculture Center. She continued her gardening education by working on organic farms in both rural and urban settings. She started UrbanOrganicYield.com to share gardening tips and tactics. She’s happy to talk about succulents and houseplants or vegetables and herbs – or just about anything in a backyard garden or hydroponics garden.