seeds that come from Papaver somniferum,
a yellowish-brown opium
plant indigenous to the Mediterranean
. Poppies are grown today in Holland, Canada, Asia, the Middle East and the Mediterranean.
Many of the poppy seeds used in cooking today come from Holland. Known as Holland Blue Poppy, these seeds are blueish-gray in color. They are often used in various baked goods.
Often used in Indian cooking are white poppy seeds. Less sweet than blue poppy, they are used to add thickness, texture and flavor to sauces.
(information gathered from aros.net and penzeys.com)