a squat tin of amber grafting compound that sets only at a junction made between two species that do not share a family.

The canister contains a resinous compound of ordinary appearance and is workable at room temperature. When applied to bark wounds, cut ends, or to inert substrates, it remains tacky and can be wiped away without leaving a skin. It hardens within twelve minutes when used to seal a graft union between two living species that do not share a botanical family. Setting occurs even when cambial layers are intentionally misaligned and even when the scions are dead at the time of binding. The hardened compound becomes glassy and adheres to both tissues; it cannot be re-softened by warming. At unions sealed with the compound, a continuous callus forms within four days and produces a stable vascular connection by the tenth. The resulting composite survives routine pruning. Flowering and fruiting, when produced, follow the scion, but the pedicels carry epidermal characters of the stock. The mass in the can decreases only in proportion to hardened product removed from unions; no shrinkage occurs from exposed samples left in open dishes.