Note: Information is dated. Do not rely on it.Poppy. The common name for plants of the genus Papaver. The species of poppy are herbaceous plants, all bearing large, brilliant, but fugacious flowers. The white poppy yields the well-known opium of commerce. Most of the species are natives of Europe, and four are truly natives of Britain. They often occur as weeds in fields and waste places, and are frequently also cultivated in gardens for ornament. The roots of the poppy are annual and perennial. The calyx is composed of two leaves, and the corolla of four petals; the stamens are numerous, and the capsule is one-celled, with several longitudinal partitions, and contains a multitude of seeds.