Ferns are predominant in the undergrowth here. From a distance wood ferns looks lighter, almost fluffy because they are twice pinnate. The sword ferns however have a sturdier profile; they form longer, undivided fronds that could look like the blades of swords. They also have an extra notch just at the base of each pinnule that looks like a sword hilt. I wouldn't recommend trying to fence with them though.
UC Santa Cruz, Natural Reserve10/10/12