Viscous Resin

Choose a target or a 10 square-foot area within range. That target or area is now coated with an annoyingly-sticky, flammable sap. Creatures trodding onto the affected area must make a STR saving throw in order to move upon setting foot in the sap and any attempt to move within it. 

The sap is also quite eager to ignite: this can be used on objects to make a light source, but you probably want to use it offensively, as the coated target will take 1d6 points of damage, unless they take a full action to stop drop and roll.