This section is from the book "Wayside And Woodland Blossoms", by Edward Step. Also available from Amazon: Wayside And Woodland Blossoms: A Guide To British Wild-Flowers.
The Poppy is another of those plants concerning which it may be thought that neither illustration nor description is necessary ; but there are poppies and poppies; and though the rambler may gather a bunch of flowers from various situations and consider them all the same, a few words of description may serve to point out considerable differences.
Through the Poppy we make acquaintance with another Natural Order, the Papaveraceae, and its typical genus, Papaver. The plants comprised in the genus are annual herbs, with milky juice of a narcotic nature. The flowers are borne on very long slender stalks, and consist of two concave sepals, which are thrown off by the expanding of the four crumpled petals. The pistil, which afterwards develops into the familiar "poppy-head," is surmounted by the many stigmas which form a rayed disk.
I. The Common Poppy (P. rhoeas), which is so unpleasantly abundant in cornfields south of the Tay, has branched bristly stems and pinnate leaves, the points of the lobes directed upward and ending each in a bristle. The bristles on the flower-stalks stand out at right angles, or nearly so. This is an important character. The scarlet flowers are large (3 or 4 inches in diameter), the petals in two unequal pairs. Rays of stigma eight to twelve. Capsule smooth and short, slightly stalked above the receptacle. Flowers June to September.
II. Round Rough-headed Poppy (P. hybridum). Leaves only slightly bristly. Flower small (1 to 2 inches), scarlet, with a black patch at the base of each petal. Stigmatic rays, four to eight. Capsule more globose than the preceding species. Dry sandy and chalky fields south of Durham and Carnarvon. May to July.
III. Long Prickly-headed Poppy (P. argemone). Similar to last, but smaller and weaker in all respects - in fact, our smallest species. Petals narrow and paler in colour. Capsule bristly, club-shaped. Stigmatic rays, four to six. Cornfields. May to August.
IV. Long Smooth-headed Poppy (P. dubium). Similar to P. rhoeas, but the bristles are pressed against the stalk upwards. Flowers large, petals broad, but in unequal pairs, light scarlet. Stigmatic rays, six to twelve. Capsule slender, smooth, tapering downwards, not stalked above receptacle. Cornfields. May to August.
Papaver rhoeas. Papaveraceae.