user69: Why do plants have green leaves and not red?
For some reason, despite being able to do so for every other question I have come across (including others posted just before) I am unable to edit this post (or even to re-tag it).  Does anyone have any suggestions as to why this would be?  
Also, can someone from the community who isn't having problems re-tag the post as appropriate?

user6: I'm pretty sure that means there is an existing suggested edit on that post, you can't submit a second edit then.

69: <p><a href="https://biology.stackexchange.com/questions/450/why-do-plants-have-green-leaves-and-not-red">Why do plants have green leaves and not red?</a></p>

<p>For some reason, despite being able to do so for every other question I have come across (including others posted just before) I am unable to edit this post (or even to re-tag it).  Does anyone have any suggestions as to why this would be?  </p>

<p>Also, can someone from the community who isn't having problems re-tag the post as appropriate?</p>
 6: <p>I'm pretty sure that means there is an existing suggested edit on that post, you can't submit a second edit then.</p>
