[Tanegashima]

Old sci-fi book my grandparents had, long gone, and I read it when I was a kid. I remember the cover being a bright blue I think, but the thing I remember most was that there was an alien character in the story that looked like a plant/crystal/coral and spoke through a genetic microphone or something, it was described like a coral or something, and it was huge...damn I know this description sucks, but I just cant get it out of my head. I also remember that the main character was a guy from earth who was sent out to make contact or something with these aliens...I'm also confident if I remember correctly that there was a political party in the book that did not like aliens and there was a lot of planets described in the novel, other than the talking aliens