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  • A new study published in Nature Communications confirms that Saxifraga candelabrum is a carnivorous plant, proving a hypothesis Charles Darwin made over a century and a half ago.
  • Experiments demonstrate the plant uses scent to attract small insects while sparing larger pollinators, then digests them using enzymes similar to those found in other known meat-eating flora.
  • The findings suggest that carnivory may be more common in the plant kingdom than previously understood, potentially extending to other species within the Saxifraga genus.

A significant gap in botanical history has been filled with the publication of new research confirming a prediction made by Charles Darwin more than 150 years ago. The renowned naturalist hypothesized that certain plants within the Saxifraga genus possessed carnivorous traits, yet he was unable to provide conclusive proof before his death. A recent study, published in the journal Nature Communications on August 4, offers definitive evidence that at least one species of this genus does indeed capture and digest animals, thereby meeting the strict scientific criteria for carnivory.

The plant at the center of this investigation is Saxifraga candelabrum, a species native to the high-altitude regions of China’s Hengduan Mountains. For a plant to be classified as carnivorous, it must successfully attract, capture, and digest animal prey. The research team found that mature specimens of S. candelabrum had an average of 71 insects adhering to the sticky hairs on their flowering branches. In contrast, juvenile plants with fewer branches trapped few or no insects, suggesting a direct correlation between the density of glandular hairs and the plant’s ability to ensnare prey.

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To understand how these plants operate, researchers conducted controlled experiments involving glass and mesh enclosures. These tests revealed that S. candelabrum relies on odor rather than visual cues to lure insects. The study also highlighted a sophisticated selectivity in the plant’s trapping mechanism. While small insects were frequently caught, effective pollinators were rarely ensnared. This distinction indicates that the plant has evolved to target minor pests for nutrition while preserving the larger insects necessary for its reproductive success.

Chemical analysis provided further insight into the digestive process of S. candelabrum. The researchers identified the presence of phosphatase, an enzyme commonly associated with digestion in other established carnivorous plants. To confirm that the plant actually absorbs nutrients from its victims, scientists labeled fruit flies with a specific nitrogen isotope. Subsequent measurements showed a rise in nitrogen levels within the treated S. candelabrum plants, whereas control plants did not exhibit this increase. This isotopic evidence confirms that the plant derives nutritional benefit from the insects it captures.

Genetic analysis added another layer of confirmation to the findings. The study revealed that S. candelabrum shares specific genes with other known carnivorous species. These genomic similarities provide independent support for the classification of the plant as a true carnivore. The convergence of behavioral, chemical, and genetic data strengthens the conclusion that Darwin’s initial intuition was correct, despite his inability to verify it during his lifetime.

The implications of this discovery extend beyond validating a historical hypothesis. Doug Soltis, a botanist at the University of Florida and co-author of the study, described the confirmation as both humbling and exciting. He suggested that carnivory might be far more widespread in the plant kingdom than current botanical records indicate. Given that other members of the Saxifraga family also possess sticky hairs, Soltis expressed confidence that additional species within this group may also exhibit carnivorous behavior, just as Darwin originally predicted.

Susan Myers, a botanist at the Pittsburgh Botanic Garden who was not involved in the research, noted that these findings underscore the surprising complexity of plant biology. She emphasized that scientific understanding of the botanical world remains incomplete, with much still to be discovered about how plants interact with their environment. The confirmation of carnivory in Saxifraga serves as a reminder that even well-studied groups of organisms can harbor unexpected adaptations.

This study marks a rare instance where modern technology and methodology have been able to settle a question left open by one of history’s most influential scientists. By combining field observations with laboratory experiments, the researchers have not only proven Darwin right but also opened new avenues for exploring the diversity of plant survival strategies. The discovery challenges existing assumptions about which plants are capable of meat-eating behavior and invites further investigation into the evolutionary pathways that lead to such traits.

As scientists continue to analyze the data, the focus may shift toward identifying other potential carnivorous species within the Saxifraga genus and related families. The use of isotopic labeling and genetic sequencing in this study provides a template for future research into plant-animal interactions. These methods allow for precise verification of nutrient uptake and evolutionary relationships, tools that were unavailable to Darwin during his era. The work represents a bridge between historical naturalism and contemporary molecular biology.

The publication of these findings adds a new chapter to the story of S. candelabrum, transforming it from a curious high-altitude flower into a recognized member of the carnivorous plant community. This reclassification may influence how botanists approach the study of other plants with similar physical characteristics. The research demonstrates that careful observation, combined with rigorous testing, can still yield major discoveries in fields that have been studied for centuries.

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  • Smithsonian Magazine↗Charles Darwin Theorized That These Plants Were Carnivorous 150 Years Ago. A New Study Proves Him Right