Hand-pollination involves gathering pollen from plants living in places that even goats cannot reach, so scientists use climbing gear to lower themselves down rock faces to reach the flowering plants. There were additional complications: pollen from another silversword was required; this species cannot self-pollinate but requires a second individual for successful reproduction. The process requires a scientist to locate a blooming plant, rappel over the cliff, dangle from a rope on the rock face, gently collect in a vial the tiny yellow grains from the flower, and then find a second flowering Mauna Kea silversword. A small brush is used to paint the pollen on the flower of the second plant. If no other plant is in bloom, the pollen is stored.