Safflower is a plant that is cultivated for the oil made from its seeds. The seeds are small and white. The name of the plant is probably related to the fact that the flowers are used as a cheap substitute for saffron (which is made out of the saffron crocus).
There is not much information to find on safflower oil on Pesach. Quite a lot of answers on "help, what oil can I use on Pesach" contain safflower oil. Maybe because the "seed" part is usually not included in the name (as opposed to cottonseed oil or sunflower seed oil), it passes under the radar of most people [pure speculation of course].
I found one statement by the cRC: "We do not have record of safflower oil being used for food purposes at the time of the minhag starting, and therefore assume it is permitted. [If you have reason to believe otherwise, we would happily reconsider this position.]" (cRc FAQ for Pesach Guide 2012)
Safflower seed oil is on none of the kitniot lists I checked. So enjoy!
- Danger of chametz traces: No.
- Danger of confusion with chametz (raw): No.
- Danger of confusion with chametz (processed): No (oil).
- Botanical categorization: Asteraceae, flower
- Known in 13th century: Yes.
- Verdict: Not kitniot.