- Name also: Corn Poppy, Field Poppy, Flanders Poppy, Red Poppy, Corn Rose
- Family: Poppy Family – Papaveraceae
- Growing form: Annual herb.
- Height: 30–60 cm (12–25 in.). Stem leafy, with spreading, rigid hairs.
- Flower: Regular (actinomorphic), 7–8 cm (2.8–3.2 in.) wide. Petals 4, red, sometimes with dark blotch at base. Sepals 2, fall as flower opens. Stamens many. Pistil of several fused carpels. Flowers solitary, terminating scape.
- Leaves: Alternate, stalked. Blade elliptic–obovate, pinnately lobed, at least lower leaves’ lobes wide and blunt. Uppermost leaves with long central lobe.
- Fruit: Barrel-shaped, 7–19 mm (0.28–0.76 in.) long, glabrous capsule. Stigma-disc with 7–16 rays.
- Habitat: Harbours, cereal fields, rubbish tips, roadsides, wasteland and yards. Also ornamental.
- Flowering time: July–August.
- Harmfulness: Potentially or locally harmful alien species.
Common poppy is quite a rare casual plant in Finnish nature, although it can appear en masse from seed bank to freshly ploghed fields. Common poppy’s wonderful red flower can hardly fail to be noticed by the human eye, but bees see it completely differently through their compound eyes. They see colours and combinations of colours according to the same principles as humans, but they use a different area of the colour scale and spectrum. A bee doesn’t see red at all, but on the other hand it’s able to detect ultra-violet light. It’s difficult to imagine what a poppy looks like through a bee’s compound eye. Regarding pollination, however, an insect’s sight is what really matters. Happily though, common poppy’s colour is also pleasing to the human eye, and the species is a reasonably popular ornamental.
Common poppy resembles its relative long-headed poppy (P. dubium), but they can be most easily differentiated on the basis of the form of the fruit of their capsule. There are also small differences in the hairiness of the stem and, in the size and colour of the corolla. Common poppy is the national flower of Poland.