Adenium obesum, commonly known as the desert rose, belongs to the Apocynaceae family, which includes other notable plants like oleander and periwinkle. Unlike many succulents, which are primarily classified under Crassulaceae (e.g., jade plants) or Cactaceae (e.g., cacti), Adenium stands out due to its unique family lineage. This classification influences its growth patterns, flowering habits, and toxicity, as many Apocynaceae members contain toxic latex.
Stem and Caudex: Adenium obesum is distinguished by its swollen, bottle-shaped caudex (stem base), which stores water—a trait shared with some caudiciform succulents like Pachypodium. However, most succulents, such as Echeveria or Aloe, store water in their leaves rather than stems.
Leaves: Unlike the thick, fleshy leaves of typical succulents (e.g., Sedum), Adenium has glossy, ovate leaves that are semi-succulent and deciduous in dry seasons. This contrasts with evergreen succulents like Haworthia.
Adenium obesum produces vibrant, trumpet-shaped flowers in shades of pink, red, or white, resembling those of oleander. This is distinct from the smaller, clustered blooms of many succulents (e.g., Crassula). Additionally, Adenium flowers are often larger and more showy compared to the modest blooms of cacti or Sempervivum.
Growth Rate: Adenium grows relatively slowly compared to fast-spreading succulents like Kalanchoe daigremontiana. Its caudex develops over years, whereas many succulents propagate rapidly via offsets or leaf cuttings.
Drought Tolerance: While both Adenium and other succulents are drought-resistant, Adenium’s caudex allows it to survive longer dry spells. In contrast, leaf-succulents like Agave rely on rapid water absorption during rare rains.
Adenium obesum contains toxic cardiac glycosides, a trait common in Apocynaceae. This contrasts with non-toxic succulents like Echeveria or mildly toxic ones like Euphorbia (which exude irritant latex). The toxicity deters herbivores, a defense mechanism less prevalent in non-Apocynaceae succulents.
Adenium is typically propagated via seeds or cuttings, with seeds being preferred to maintain caudex shape. Many other succulents, such as Graptopetalum, easily propagate from leaves or offsets, making them more beginner-friendly.
Soil: Adenium requires well-draining soil with higher organic content compared to gritty mixes used for cacti or Lithops.
Temperature Sensitivity: Unlike cold-hardy succulents (e.g., Sempervivum), Adenium is highly sensitive to frost and thrives in tropical or subtropical climates.
