Adenium obesum

Description

It is an evergreen or drought-deciduous succulent shrub (which can also lose its leaves during cold spells, or according to the subspecies or cultivar). It can grow to 0.12 – in height, with pachycaul (disproportionately large) stems and a stout, swollen basal caudex (a rootstock that protrudes from the soil). The leaves are spirally arranged, clustered toward the tips of the shoots, simple entire, leathery in texture, 5 – long and 1 – broad. The flowers are tubular, 2 – long, with the outer portion 4 – diameter with five petals, resembling those of other related genera such as Plumeria and Nerium. The flowers tend to be red and pink, often with a whitish blush outward of the throat.

Taxonomy

Some taxonomies consider some other species in the genus to be subspecies of Adenium obesum.

Subspecies

• Adenium obesum subsp. oleifolium (South Africa, Botswana)
• Adenium obesum subsp. socotranum (Socotra)
• Adenium obesum subsp. somalense (Eastern Africa)
• Adenium obesum subsp. swazicum (Eswatini, South Africa)
• Adenium obesum subsp. Arabicum (Saudi Arabia, Yemen)

Adenium swazicum is a critically endangered African species native to Eswatini and Mozambique, growing up to 0.7 m (2.29 ft) tall.

Adenium somalense is also native to Africa, inhabiting Tanzania, Kenya, and Somalia, and reaching heights of 5 m (16.40 ft), which makes it the largest of these four subspecies.

Adenium socotranum is native exclusively to the island of Socotra, and can grow to be 4.6 m (15 ft), but despite its small range, it is of least concern regarding endangerment. It can swell up to 8 feet (2.5 meters) in diameter at the base.

Adenium oleifolium is near threatened in the wild and is the smallest of these subspecies, growing at the tallest to 0.4 m (1.31 ft).

Adenium Arabicum a species is a monoecious and self-sterile, common names include desert rose, elephant's foot, and Adan bush, arabicum is native to Saudi Arabia and Yemen.

Ecology

Caterpillars of the polka-dot wasp moth (Syntomeida epilais) are known to feed on the desert rose, along with feeding on oleanders.

In areas with year-round warm weather, they can bloom throughout the year.

Uses

Adenium obesum produces a sap in its roots and stems that contains cardiac glycosides. This sap is used as arrow poison for hunting large game throughout much of Africa and as a fish toxin.

Cultivation

Adenium obesum is a popular houseplant and bonsai in temperate regions. It requires a sunny location and a minimum indoor temperature in winter of 10 C. It thrives on a xeric watering regime as required by cacti. A. obesum is typically propagated by seed or stem cuttings. The numerous hybrids are propagated mainly by grafting on to seedling rootstock. While plants grown from seed are more likely to have the swollen caudex at a young age, with time many cutting-grown plants cannot be distinguished from seed-grown plants. Like many plants, Adenium obesum can also be propagated in vitro using plant tissue culture.

This plant has gained the Royal Horticultural Society's Award of Garden Merit.

Symbolic and cultural references

The species has been depicted on postage stamps issued by various countries.

Gallery

File:Bottle Trees, Socotra Island (9888518324).jpg|Close-up of stand of A. obesum var. socotranum, Socotra File:Desert Rose, Socotra Is (17131661372).jpg|A. obesum var. socotranum, trunk of single extreme pachycaul specimen, Socotra File:Desert rose Adenium obesum in Tanzania 2259 Nevit.jpg|Group of plants growing in scrubland, Tanzania File:Adenium obesum - Marie Selby Botanical Gardens - Sarasota, Florida - DSC01083.jpg|Cultivated bonsai specimen with picturesquely contorted caudex and roots, Florida File:RCN Mother.jpg|Cultivated specimen in Thailand flowering profusely. File:Adenium Fruit 15+16cm Panorama Chennai Jun21 D72 20060+63 Pano.jpg|Large fruits on 30-cm tall plant, Chennai. File:Adenium seedling 2day Uthandi Aug21 D72 20609-21 ZP.jpg|2-day seedling with seed husk 15 mm, Chennai. File:Adenium obesum plants at the campus of Ramakrishna Mission Vidyamandira in Belur Math, Howrah.jpg|Group of plants at the campus of Ramakrishna Mission Vidyamandira in West Bengal, India. File:العدنة Adenium Arabicum.JPG|Adenium Arabicum Tree, Tihama, Jizan, Southwest Saudi Arabia

References

References

1. Botanic Gardens Conservation International (BGCI).. (2019). "''Adenium obesum''".
2. {{GRIN
3. Schoch, C.L.. (2020). ""Adenium obesum", NCBI Taxonomy: a comprehensive update on curation, resources and tools".
4. Siby Xavier. (23 October 2024). "Meet the Majestic Adenium Socotranum: Socotra's Floral Gem".
5. (August 2006). "Oleander caterpillar (Syntomeida epilais)".
6. "Is Adenium Obesum Poisonous to Dogs?".
7. Schmelzer, G.H.. (2008). "Medicinal Plants". Plant Resources of Tropical Africa.
8. John 'Lofty' Wiseman ''SAS Survival Handbook, Revised Edition'' p. 240; William Morrow Paperbacks (2009) {{ISBN. 978-1875900060
9. D'Cruz, Mark. "Ma-Ke Bonsai Care Guide for Adenium obesum". Ma-Ke Bonsai.
10. (5 December 2010). "In vitro Propagation of Adenium obesum (Forssk.) Roem. and Schult.". Notulae Botanicae Horti Agrobotanici Cluj-Napoca.
11. "RHS Plant Selector - ''Adenium obesum''".
12. "Adenium obesum".