Yellow-juiced Poppy - Papaver lecoqii

Visually identical to Long-headed Poppy (Paper dubium) and was treated as a subspecies (Papaver dubium ssp. Lecoqii) until the publication of new names and taxa in the third edition of Stace which changed it to Papaver lecoqii. The test for Papaver lecoqii is to break and squeeze the stem so that the juice becomes visible. In Papaver lecoqii this is quite a bright yellow, although it may need 30 second or so to become obvious - (the juice is white in Papaver dubium).

all other small red poppies; especially P dubium

Seed capsules long and narrow (more than twice as long as wide).  Yellowish sap or latex, when fresh - break stem to see this. Anthers often yellowish

Photo of seed capsules, and fresh latex oozing from broken stem.  Cannot be identified from a photo just of the flower

Disturbed ground of any type.

June to August.

Annual.

Fairly widespread in Britain, particularly in southern central England.

Occasional in Leicestershire and Rutland though easily overlooked. The Flora of Leicestershire published in 1988 states that it occurred in 23 of the 617 tetrads.

In the current Checklist (Jeeves, 2011) it is listed as Alien (archaeophyte) and Occasional