Plebejus argyrognomon - Reverdin's Blue - Kroonkruidblauwtje - Kronwicken-Bläuling

​The male upperside is violet-blue with narrow black borders and white fringes. The rear edge of the hindwing may have some small black spots just inside the black border. The female upperside is brown with orange submarginal lunules which be missing in the forewing. The hindwing has black marginal spots and both wings hav an extensive blue flush. Th male underside is pale grey or almoast white with an orange submarginal band. The female underside has the same pattern as the male but the ground colour is pale greyish brown and the orange band is well developed on both wings. Flight from May to September in two broods on rough grassland from sea level to about 1500 m. The main larval foodplant is Crown Vetch.