Answer:
I am flora not fauna. I am foliage not trees. I am shrubbery not grass.
Born in the ocean and white as snow. When I fall back to water, I disappear without a trace. What am I?
I don't live within a house nor do I live without. Most will use me when they come in and again when they go out.
Sometimes dark and sometimes bright I make my way among twinkling lights. Seas and oceans obey my call yet mountains I cannot move at all. My face is marred and gray But I'm majestic anyway
I have a strong affection for belly buttons.
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.