Abstract text: In myxospermous seeds, hydration initiates mucilage expansion followed by a dehydration-induced network collapse that facilitates substrate attachment. While the ecological role of mucilage in dispersal is established, the biophysical mechanisms governing its interfacial attachment remain poorly defined. We hypothesized that attachment is driven by a synergy of molecular interactions at the mucilage-substrate interface and the formation of internal microstructures resulting from shrinkage during water loss. To test this, we probed interfacial interactions through chemical and enzymatic perturbation, coupled with rheology and a custom-built attachment assay. We also used high-resolution fluorescence microscopy and scanning electron microscopy to visualize mucilage organization in the hydrated and dehydrated states, respectively. Chemical perturbation experiments revealed that attachment depends on cooperative electrostatic, hydrophobic, and calcium-mediated cross-linking interactions. Furthermore, enzymatic degradation confirmed that pectin removal leads to a critical failure of attachment. Our findings support a model in which seed attachment to various substrates is achieved mechanically through polymer entanglement combined with surface electrostatic and hydrophobic interactions, rather than through bulk adhesion. This study identifies the biophysical parameters for engineering new design principles for adaptive, sustainable materials in large-scale agriculture and forest restoration.