I Know Why the Caged Bird Sings by Maya Angelou, former colleague of Martin Luther King Jr., is a moving piece about black oppression in the South. It describes her young life, which she spent with her brother and grandmother. The story starts with a painful humiliation at Angelou's church, where she reveals that she hates her blackness, and though she cannot seem to properly verbalize it, she desires to be white. She then describes experiences in her grandmother's store. She gains an understanding of the struggle of being black in the South, seeing her neighbor's exhaustion, and their struggle to support their families. The painful reality is that virtually earned made enough to support their families, and they would never be able to escape the cycle of poverty that entrapped them. They always masked worry with hope in the mornings, but Angelou knew that they would always come back dejected and concerned. Everyone lived in fear of the Ku Klux Klan, and white people scared everyone, even the poorest of them seemed to have a stronghold on the blacks, no economic power could change that. The essay ends with Angelou's grandmother being humiliated by some white children, yet she achieves the impossible and rises above them, perhaps inspiring Angelou to become that powerful activist that she would become. The essay argues that in order for a person to overcome oppression, they must be morally superior to the oppressor to enact real change. When Angelou sees her grandmother once she overcomes her white oppressors, she describes her as angelic, a hyperbole to describe the woman's mental power to overcome. She uses descriptive language to convey that her oppressors are evil, yet her descriptions of them show that they are simple, and lack real power. She also uses narrative form to paint vignettes of the daily oppression that she, her family, and her friends faced. By showing her grandmother overcoming oppressors by ignoring and praying whilst they tormented her, Angelou proves her argument that to overcome tyranny, one must be morally superior to the oppressor.

(frashogard.com)
This is a picture of a plant defeating all odds and growing in a hostile environment, much like how Angelou suggests one should overcome adversity.