Thigmonasty - Mucilage Analysis - Evolution
Drosera binata (the Forked Sundew) represents a unique morphological divergence within the genus Drosera. While most Sundews possess simple leaves, D. binata exhibits dichotomous branching, ranging from simple "T-shapes" to multi-forked complexes (var. multifida). This adaptation significantly increases the surface area for prey capture relative to the plant's biomass. It is native to the sandy, acidic heathlands and peat bogs of Australia and New Zealand.
The plant utilizes an "active flypaper" trap. The leaves are covered in stalked multicellular glands (tentacles) that secrete a mucilaginous polysaccharide. This secretion serves both to attract prey via optical refraction and to physically entrap them. Upon tactile stimulation (thigmotropism), the tentacles curve inward to secure the prey, and in D. binata, the leaf lamina itself can slowly curl around larger prey items. This maximizes contact with sessile digestive glands, which release esterases, peroxidases, and chitinases for nutrient absorption.
