Description: Annual, biennial or perennial herbs, latex frequently colourless.
Leaves forming a basal rosette when young, alternate on stems.
Flowers solitary, on long peduncles; buds drooping. Sepals 2, shed early. Petals 4. Ovary 1-locular; carpels several; stigmas several, sessile, in radial rows on a disc on top of the ovary.
Capsule dehiscing by pores; seeds numerous.
Distribution and occurrence: World: c. 100 species, cosmopolitan. Australia: c. 6 species (c. 5 species naturalised, 1 species doubtfully native), all States.
Text by S.W.L. Jacobs
Taxon concept:
| | Key to the species | |
| 1 | Capsule with numerous bristles | 2 |
| Capsule glabrous | 3 |
| 2 | Capsule 10–12.5 mm long, 10–15 mm diam., subglobose to ovoid | Papaver hybridum |
| Capsule 15–20 mm long, 3–5 mm diam., oblong
Back to 1 | Papaver argemone |
| 3 | Capsule at least twice as long as broad, 6–8 mm diam | 4 |
| Capsule no more than twice as long as broad, 10 mm or more diam
Back to 1 | 5 |
| 4 | Capsule c. 15 mm long, with 4–8 stigmatic rays | Papaver aculeatum |
| Capsule 15–25 mm long, with 6–10 stigmatic rays
Back to 3 | Papaver dubium |
| 5 | Stem leaves sessile, clasping stem | Papaver somniferum |
| Stem leaves shortly petiolate, petiole usually winged
Back to 3 | Papaver rhoeas |
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