Secondary Hematophagy in the Bromeliad Acanthostachys cruentus

The remote, tabletop mountains or tepuis of Venezuela are home to some of the world’s most unique and isolated flora. A recent botanical expedition has identified a new species of bromeliad, Acanthostachys cruentus, that employs a carnivorous strategy far more complex and macabre than any previously known. This botanical innovation lies in its two-stage trapping mechanism, which begins with the razor-sharp, silica-hardened leaves that form its central water-collecting cup. The serrated perimeter of each leaf forms a literal bleeding edge.

The primary trapping mechanism is not digestive fluid, but a specialized nectar secreted along the leaf edges. This nectar contains powerful phytochemical anticoagulants. When a small vertebrate, like a lizard or mouse, brushes against the leaves, it receives dozens of tiny, shallow cuts. The anticoagulant nectar drips into these wounds, preventing them from clotting and causing the animal to continue bleeding as it moves away. The scent of blood then serves as a powerful attractant for the true target: hematophagic (blood-eating) insects and other small scavengers. As these creatures swarm to the bleeding animal, many of them inevitably fall into the plant’s central cup, where they are drowned and digested.

This strategy of “secondary hematophagy”—using one animal’s blood to attract another—is a high-risk, high-reward evolutionary gamble. The plant does not get an immediate meal and is dependent on the local insect population. However, a single successful trapping event provides the plant with a massive nutrient infusion, far greater than what it could gain from trapping insects directly. It represents a new and startlingly complex evolutionary pathway for carnivory in the plant kingdom.