For old Irish names I would have thought Gallic-Druidic cultural associations might have some sort of currency or influence. Maybe try looking for research with those conceptual frames of reference. Here's an example query to place with your favourite LLM: "make a list of the top 30 plants associated with traditional herbal lore in pre-modern ireland. seek gallic/druidic associations through etymology, lore and written record (if feasible). table format."