conferruminate
Closely united by the coalescence of contiguous faces.
The cotyledons of the live-oak acorn are conferruminate.
Where it comes from
First attested in 1826; borrowed from Latin conferrūminātus, perfect passive participle of conferrūminō (“to cement”) (see -ate (verb-forming suffix) and -ate (adjective-forming suffix)), from con- + ferrūminō, from ferrūmen (“cement”) + -ō (verb-forming suffix).
Adapted from the Wiktionary entry conferruminate (CC BY-SA 4.0).