cinnamon fern

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A New World fern (Osmunda cinnamomea) having narrow, spore-bearing, cinnamon-colored leaves in early spring, which are later encircled by wider sterile green leaves.

Wiktionary

1. n. A coarse fern, Osmunda cinnamomea, found primarily in wet areas.

WordNet 3.0

1. n. New World fern having woolly cinnamon-colored spore-bearing fronds in early spring later surrounded by green fronds; the early uncurling fronds are edible