larch

Larch comes from early modern German Larche/Lärche, from Middle High German larche, from Old High German larihha, from Proto-West Germanic *larikā — itself an early borrowing from Latin larix, which came from Ancient Greek λάριξ (lárix), possibly of Gaulish origin.

The word seems to have kept a fairly stable meaning throughout its history, simply naming the same kind of tree as it passed from Greek into Latin, then into the Germanic languages, and finally into English.

The facts given don't point to any other English word sharing this root, so larch stands on its own as far as known cognates go.