What kind of iceberg can be eaten completely in one meal?

I'm long and green, a garden delight, But some say my shape is a bit impolite. I'm cool in a salad, a refreshing bite, But what am I, causing such lyrical plight?

I’m crooked in posture and humble in size, a shelter that doesn't pretend. When rain forms streams and wind sighs, travelers may call me a friend.

Whether a single shed, Or a red path to bed. The seer of counting ‘love-me’s, Plucked from atop the head.

I won't say a thing, my lips are sealed all day, every day. And I live under the sea, so you would hear me anyway.