Roridulaceae

Roridulaceae is a small family of carnivorous plants comprising three extant species within a single genus, Roridula. These plants are native to South Africa’s Cape Floristic Region, where they thrive in nutrient-poor, sandy soils. Roridulaceae are notable for their unique insect-trapping mechanism, which involves sticky glandular hairs on their leaves to capture prey.

The members of this family are perennial, woody shrubs characterized by lance-shaped leaves covered with glandular hairs that produce a sticky, resinous substance. These plants produce clusters of small, tubular flowers that are typically white or pale pink, with several stamens and a single style. The flowers are often borne on a leafy inflorescence, blooming mainly during the spring and summer months.

Roridula species are obligate insectivores, relying on their sticky hairs to trap insects such as ants and flies. Unlike some other carnivorous plants, Roridula does not produce enzymes to digest prey. Instead, it depends on mutualistic associations with hemipteran insects, particularly assassin bugs (Reduviidae), which feed on trapped prey and, in turn, excrete nutrient-rich honeydew. These excretions are absorbed by the plant’s leaves, supplementing its nutrient intake in the nutrient-deficient environment.

Taxonomically, Roridulaceae was traditionally placed within the order Passiflorales but is now classified under the order Ericales, along with other families of Carnivorous and non-carnivorous plants. The family exhibits significant adaptations to its environment, making it an intriguing example of evolutionary specialization among carnivorous plants.

Overall, Roridulaceae represents a distinctive group of carnivorous plants with specialized ecological relationships and adaptations suited to their unique habitat.