You cause all blades of low-lying (3-inches tall or less) grassy plants within the spell area to become as sharp as knife blades. Casually walking through such an area causes 1d2 points of damage, unless metal boots or magical footwear is worn. Any foot so damaged requires 1d4 days of mundane healing, and causes a 25% reduction in movement rate during that time. Falling into bladed grass is more destructive, causing 1d8 points of damage (unless covered in plate mail).
You cannot be hurt by the bladed grass, and can dispel it at any time before it expires.
The component of this spell is dagger and a piece of grass from the patch to be bladed. The dagger is not consumed in the casting, but the piece of grass is.
This spell can be made permanent with a permanency spell (Minimum Caster Level 10th, XP Cost 1,000).