unassuming marigold

Reader's Digest 1月号に広大なマリーゴールド畑の写真が載っていました。
The cheerful, unassuming marigold, a member of the sunflower family, has been caltivated in Mexico since Aztec times.
"unassuming" は "not sssuming" だと思いますが、推測する "assume" しか知らないので unassuming" の意味が分かりません。 まず "unassuming" を辞書で引きます。
・Merriam-Webster's Online Dictionary: not assuming : modest: an unassuming librarian; an unassuming manner; an unassuming neighborhood
・Cambridge English Dictionary: Someone who is unassuming is quiet and shows no wish for attention or admiration: He was shy and unassuming and not at all how you expect an actor to be.
やはり "assuming" に私が知らない次ぎの意味がありました。
・Vocabulary.com: If someone accuses you of being assuming, he or she thinks you are arrogant or that you take too much for granted. If you take on an assuming tone when you ask for something, people are more likely to feel offended than to be generous.
"assuming" と "unassuming" の意味を対で覚えましょう。