jwt verify always returns 'jwt malformed'

I am working on an android app that uses google+ OAuth2 for authentication and a node js backend/API that needs to be secured. I have decided to use google+ tokens and by sending them along with each api call, I want to verify that the token really is from google. I am currently using jsonwebtoken from the npm and a google pem file from this link.

The problem I am getting is that whenever I verify the token, I always receive an error:

{ name: 'JsonWebTokenError', message: 'jwt malformed' }

Here's my code on the node side:

var verifyToken = function(token) {

  var cert = fs.readFileSync(__dirname + '/googlepublic.pem');

  try {
    //returns a JsonWebToken
    var decoded = jwt.verify(token, cert);
  } catch(err) {
    // err
    console.log(err);
    return "false";
  } 
  console.log("I received response for verifyToken! " + decoded);
  return decoded;
}

I know the token is right because I've verified with the google verification endpoint before, I just want to be able to verify locally.