In the ancient forest at Prairie Creek Redwoods State Park in northern California, you walk beneath some of the tallest trees on the planet, immersed in a green-on-green world dripping with ferns, their amazing fiddleheads unfurling in the spring. Ferns cover the forest floor, drape from the branches and trunks of the trees and line the 50-foot walls of the world-famous Fern Canyon.

Waist-high sword ferns surround our campsite, delicate deer fern and lacy lady fern line the sides of the trails. The deer fern has two types of fronds, sterile ones with broader leaflets, and reproductive fronds with much narrower leaflets that contain spores on their undersides.

Leather fern form mats in the redwood canopy, creating hanging gardens with up to six feet of soil and blooming blackberry bushes. Bracken ferns cover the prairie, nearly hiding the reclining elk munching there. And in Fern Canyon, a World Heritage site and an International Biosphere Reserve, five-finger ferns flutter from canyon walls.