Seeking a short story I read in a collection at least 5 or 6 years ago, can't trace the name or origin. Please help! Here's what I remember:
Race of sentient trees (looks like a normal forest to us). One way they communicate is by changing the colour of their leaves. One is taken by the humans and kept on earth, thinks of itself a bit like a diplomat, but it takes the humans about 50 years to realize the colours don't change randomly and the tree is aware. Only other things I remember are the aliens think of our redwood forests as extremely special needs versions of themselves - cousins basically, stunted and broken by their location (they are not sentient, too).