mystery plant leaf
 

A friend recently sent me this leaf for identification. [ they must be
confused if they think i know stuff :( ].

http://tinypic.com/view.php?pic=otnr87&s=4


It 'was' quite green apparently, but since lying about has turned a yellowy
colour. The spine is black and quite a hard material. The lines at right
angles to the length are just where it's been folded to go in an envelope
for posting.

Grateful for any info on what plant this might be please, thanks.