All true ferns come out of the ground head foremost, coiled up like a
watch-spring, and are designated as "fiddle-heads," or crosiers. (A real
crosier is a bishop's staff.) Some of these odd young growths are covered
with "fern wool," which birds often use in lining their nests. This wool
usually disappears later as the crosier unfolds into the broad green blade.
The development of plant shoots from the bud is called vernation (Latin,
_ver_ meaning spring), and this unique uncoiling of ferns, "circinnate
vernation."