3.5 SRD wrote
Woodland Stride (Ex): Starting at 2nd level, a druid may move through any sort of undergrowth (such as natural thorns, briars, overgrown areas, and similar terrain) at her normal speed and without taking damage or suffering any other impairment. However, thorns, briars, and overgrown areas that have been magically manipulated to impede motion still affect her.
Woodland stride works in overgrown areas (which were coded by Tissa for area builders). We decided to make it also work on Entangle, even though it should not. However Grease is a magical effect, and webs are either magical in nature or created by creatures. Neither is an overgrown area, so woodland stride has no effect in them.— dougnoel, Systems Coder