ETYMOLOGY
so called because of their resemblance to the seeds of a fern:
perhaps from fern + -ticle (as in particle, etc.)
EXAMPLE
“…It healeth al the fautes in the face layd to with hony, and it taketh away frekles or fayrntikles with vinegre …”
From: A New Herball
By William Turner, 1551
Lexicophilia 