Where does “*cistulāre” come from?

*cistulāre (Vulgar Latin) comes from Latin fistulāre, from Latin fistula, from Proto-Indo-European bʰeyd-, from Proto-Indo-European bʰey- — bee.

Ancestry of “*cistulāre”, step by step

StepLanguageWordMeaning
1Latinfistulāre
2Latinfistulapipe, tube, especially a water pipe; hollow reed...
3Proto-Indo-Europeanbʰeyd-to split
4Proto-Indo-Europeanbʰey-bee
Every word from Proto-Indo-European bʰey-Every word from Proto-Indo-European bʰeyd-Every word from Latin fistula