Pink hibiscus plant
As Morrie's body deteriorates, so does the condition of the hibiscus plant. The plant's pink petals wither and fall as Morrie grows increasingly dependent on his aides and on oxygen. As his death approaches, so does the death of the plant. It is continually used as a metaphor for Morrie's life and for life itself. Like the plant, humans, Morrie in particular, experience a natural life cycle, which inevitably ends in death. Morrie must accept this inevitable fate, as must Mitch.
Waves on the ocean
Morrie recounts a story he had heard about a small wave seeing the waves ahead of him crash on the shore, disappearing into nothingness. He suddenly brims with fear upon the realization that he too will soon 'crash on the shore' and, die as the wave fears he will. This little wave confides his fear in another wave who comforts him with the news that he will not crash and die, but will instead return to become a small part of the larger ocean. This small wave is symbolic of Morrie, as he too is on the brink of crashing into a theoretical shore, a symbolic embodiment of his death. Like the wave, Morrie is comforted by the knowledge that he will soon return to something larger in the afterlife. Morrie's affinity for the parable denotes his belief in a form of reincarnation, which he understands as intrinsic part of the natural life cycle.
Morrie's aphorism, "When you're in bed, you're dead," eventually comes true. Throughout Morrie's struggle with ALS, he refuses to stay in bed, as he sees it as a form of surrender, and instead opts to rest in the chair in his study. Morrie intends to live his last days as fully as he can, and knows that if he is to remain in bed, he will surrender himself to death by forfeiting the simple enjoyment he gets from lying in his study. In his study, photographs of loved ones, and the books he has collected in his lifetime surround Morrie. There, he can look outside of his window, and though he cannot go outside, he admires the beauty of the seasons and the plant and animal life outdoors. It is not until Morrie's final days that he does stay in bed, when he has at last accepted and readied himself for death.