An alien flower is in The CW series Roswell, New Mexico. Its pollen inhibits alien powers.
The flower has blue-purple leaves and yellow pollen.
It is extremely rare, initially thought to only grow in one spot in the Libyan desert, and Liz Ortecho is unable to find fresh flowers. Michael Guerin finds some growing over the grave of Louise Truman at the Navajo reservation, and he suspects that the flower only grows where there are alien remains. Since some grow in Libya, it indicates the possibility of another alien ship coming to Earth there.
The yellow pollen of the flower inhibits alien powers. Noah Bracken uses the pollen to trap Michael and Max Evans in Michael's bunker. Liz uses the pollen against Noah when he attacks her at the Crashdown. Kyle steals the pollen and mixes it into his mother's perfume so that her mind can't be messed with by aliens. Maria's family necklace contains a flower that prevents them from using their powers and developing a degenerative brain condition. Michael later makes a bracelet for Maria with the pollen in the beads to keep Maria safe.