Latex or coloured sap
Many members contain latex or coloured sap. In Common Poppy the latex is white, while other members of the family may produce yellow or orange sap.
Common Poppy
Papaver rhoeas
Family: Papaveraceae
Flowering: June, July, August
Plant family guide
The poppy family
Papaveraceae contains poppies as well as fumitories and several other groups. Many of the familiar poppy-type members are easy to recognise from their coloured or milky sap, showy flowers and capsule fruits.
The Common Poppy is an excellent example of the classic poppy structure, but the family is more varied than poppies alone suggest.
Key family attributes
Usually alternate leaves
Leaves are commonly arranged alternately and often deeply divided or lobed. Stipules are generally absent.
Two early-falling sepals
In the typical poppy form there are usually two sepals. They enclose the flower bud and often fall away as soon as the petals open.
Showy petals
Flowers are commonly conspicuous. Poppies usually have four free petals, although the wider family varies in petal number and flower form.
Stamens often numerous
Many poppy-type flowers have a conspicuous ring of numerous stamens. Common Poppy is a particularly clear example.
Superior ovary and capsule fruit
The ovary is usually superior and formed from fused carpels. The fruit is commonly a dry capsule containing many seeds.
Common Poppy as a Papaveraceae example
- Sap: white latex.
- Leaves: hairy, deeply lobed and mainly alternate.
- Bud: nodding and enclosed by two hairy sepals.
- Flower: four scarlet petals and numerous stamens.
- Ovary: superior, topped by a broad stigmatic disc.
- Fruit: a smooth rounded capsule releasing seeds through pores near the top.
An important family variation
Not every member of Papaveraceae looks like a poppy. Modern classifications also include fumitories, such as Common Fumitory (Fumaria officinalis). Their flowers are much smaller, bilaterally symmetrical and often spurred, so the familiar four-petalled poppy appearance is not universal across the family.
This makes features such as sap, ovary structure and fruit type useful alongside flower shape when recognising the wider family.
Compare with other families
Poppies can superficially resemble members of Ranunculaceae because both may have showy flowers and numerous stamens. In poppies, however, the sepals commonly fall as the flower opens, the carpels are fused into a single ovary, and the fruit is usually a many-seeded capsule.
Buttercup-family flowers more often have several separate carpels in the centre, which later form individual achenes or other separate fruits.
Papaveraceae flowers in this guide
Explore the individual flower pages for more photographs and identification details.