Myrmon

Myrmon is a yellow flower grown in large fields surrounding Riverside. A sleeping potion can be brewed with the centre of the flower, which is commonly used as a sedative. The stems of the flower make good feed for animals and the petals gives a yellow dye that never fades.

The Silver Door
In the alternative future of Dorne, myrmon was used by Bird to drug Dirk and Sonia so that he could take them as prisoners.

The Third Door
Myrmon had only recently begun to be grown in Riverside when Rye, Sonia, Dirk and Sholto arrived there. The people of Riverside grew the crops in large chequered fields surrounding the village of Riverside. Here it was used to brew a sleeping potion which was used as a sedative on people in pain.