Resembling or relating to plants of the fern family Blechnaceae; fern-like in appearance.
From Greek blechnon (a fern) + -oid (resembling). The Greek word blechnon is of unknown origin, but -oid is a productive suffix meaning 'resembling' or 'like,' used extensively in scientific nomenclature.
Blechnoid is the kind of hyper-specific botanical term that almost nobody uses outside of serious fern research, yet it exists because botanists love precise classification. The fact that someone decided ferns needed a special adjective shows how specialized scientific language can get.
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