As with most sensational images from Mars, this too is just an optical illusion (or so NASA’s PR department would have us believe :) ) Read the full write-up here.
![MARS_1558058c[1]](http://www.techrivet.com/content/binary/WindowsLiveWriter/NASAProbePhotographsTreesonMars_AC0E/MARS_1558058c%5B1%5D_thumb.jpg "MARS_1558058c[1]")