In a recent interview, botanist Douglas Soltis discussed groundbreaking research confirming Charles Darwin’s suspicion that a seemingly harmless flowering plant is actually carnivorous. Soltis, a University of Florida researcher, co-authored a study revealing Saxifraga candelabrum, found in southwestern China, as a predator that traps and consumes insects using its sticky hairs.
Published in the journal Nature Communications, the study validates Darwin’s 151-year-old theory about carnivorous plants within the Saxifraga genus. These plants, including the studied species, attract insects with sweet, sticky secretions on their hairs, a feature that intrigued Darwin in 1875 when he observed insects stuck to European Saxifraga plants.
To prove the carnivorous nature of Saxifraga candelabrum, Soltis and his team conducted experiments with fruit flies fed enriched nitrogen to simulate the nutrient-starved environment of mountain plants. Nitrogen is crucial for these plants, as they primarily seek this nutrient from insects rather than carbon.
The evolution of sticky hairs on these plants may have initially served as seed protection from bugs, later evolving into a means to extract nutrients from trapped insects. This unique adaptation allows Saxifraga candelabrum to target smaller insects for consumption without hindering larger insects crucial for pollination.
The study suggests that more undiscovered carnivorous plants, including those within Darwin’s favored Saxifraga genus, could exist. Past research in British Columbia’s Cypress Provincial Park revealed similar carnivorous plant behavior, indicating a broader presence of such species in nature.
With over 630 known carnivorous plant species globally, ranging from Venus flytraps to pitcher plants, the plant kingdom’s diverse methods of insect predation continue to fascinate scientists. Soltis emphasized Darwin’s fascination with these plants’ innovative strategies for obtaining nutrients and highlighted the remarkable adaptations that have evolved in the plant world.
