inconspicuous /ɪnkənˈspɪkjʊəs/ Not clearly visible or attracting attention.
Often, when I am reading through field guides, plants will be described as having "insignificant" or "inconspicuous" flowers. I myself have always been a bit of a wallflower, and so I suppose maybe I take offense to such descriptions!
Take this thyme for example...it grows rather robustly from the crevices between the rocks around our pond. It is currently in bloom...covered with the loveliest tiny pink blossoms.
All through the day and evening this diminutive plant is visited by flower flies and nectar-seeking bees. It is neither invisible nor lacking in attention. And so, I celebrate its flowers and I deem them quite significant!