Fig. 1

Floral diversity in Papaveraceae. Petal-bearing flowers in Papaver rhoeas (a), Eschscholzia californica (b) and Stylophorum diphyllum (c). d S. diphyllum floral diagram. e–m Petal-less flowers. e–h Bocconia frutescens, preanthetic and anthetic flowers. i B. frutescens floral diagram. j–l Macleaya cordata, preanthetic and anthetic flowers. m M. cordata floral diagram. Arrow gynophore; c carpel, ip inner petal, op outer petal, s sepal, st stamen, * homeotic stamen; 1, first set of 4 true stamens on the first whorl in red indicate that these are the first stamens formed and that they occupy the same positions in both petalous and apetalous species serving as reference for the positioning of all other stamens; 2, second set of true stamens of the first whorl; 3, true stamens of the second whorl. 4. True stamens of the third whorl. Bars a–c = 7 mm; e, g, h = 10 mm; f = 2 mm, j, l = 8 mm; k = 4 mm