liken, lichen

Liken or liken is an informal word meaning to compare, or to see a similarity to someone or something--
It's not a good idea to liken her to her sister--she thinks they don't even look alike.
He gets annoyed if we liken his music to something we've heard on the radio.

Lichen or lichen ( rhymes with liken ) means a small plant, something like a fungus or an alga, that grows on trees or rocks the way moss does--
He painted several studies, trying to show the colors of the lichen on the rocks.
That looks like a green and yellow hill from a distance, but it's really a large rock covered in lichen.

Now that you know that, you can say--
"If I could write a poem, I would liken the yellow lichen on the rocks to a bouquet of flowers."