Leaves clawing ?
From the pics, my first guess would be they have been over-watered and possibly although unlikely over-fed (no yellowing of the tips). Check out one of my grow sources.
http://weedfarmer.com/cannabis/
http://weedfarmer.com/cannabis/tables_guide.php
http://weedfarmer.com/cannabis/plant_abuse_guide.php
http://weedfarmer.com/cannabis/mistakes_guide.php
In the last link, IMO, the worst mistake a grower can make, all things considered, is #2.

http://weedfarmer.com/cannabis/
http://weedfarmer.com/cannabis/tables_guide.php
http://weedfarmer.com/cannabis/plant_abuse_guide.php
http://weedfarmer.com/cannabis/mistakes_guide.php
In the last link, IMO, the worst mistake a grower can make, all things considered, is #2.