phytoaccumulation

The story

1. Proto-Indo-European*bʰuH-
2. Proto-Indo-European*bʰuHyéti
3. Ancient Greekφῠ́ω (phŭ́ō)
4. Ancient Greekφῠτός (phŭtós)
5. Ancient Greekφῠτόν (phŭtón)
6. Englishphyto-
7. Proto-Indo-European*h₂éd
8. Proto-Italic*ad
9. Proto-Italic*ad-
10. Latinad-
11. Proto-Indo-European*ḱewh₁-
12. Proto-Indo-European*ḱuh₁mósder.?
13. Latincumulus
14. Latincumulō
15. Latinaccumulō
16. Latinaccumulātiō
17. Middle Frenchaccumulation
18. Latinaccumulātiō
19. Middle Englishacumulacyon
20. Englishaccumulation
21. English todayphytoaccumulation

From phyto- + accumulation.