As its name suggests, this butterfly is restricted in its European distribution to Spain, though it also flies in Morocco. Like closely related species it uses horseshoe vetch as a foodplant, though it will apparently take other Fabaceae as well. It is, however, adapted to hotter, more arid environments than most. It flies in a single brood from June to August.

In the south of Spain, subspecies albicans flies, in which males are chalky white above and below. The pictures from Antequera, above, show this subspecies. In flight the butterflies look like whites, with no blue - or indeed any other colour - visible. A similarly white subspecies, bolivari, flies in the Madrid region. In the north of Spain, subspecies arragonensis is more blue-white. Some individuals I photographed in 2017 were so blue I took them to be hybrids with chalkhill blues (and figure them on that page). Given the date (before mid-July) I could not reasonably treat them as Provence chalkhill blues and they were structurally, and in terms of their wing patterns, most similar to Spanish chalkhills. Hybridisation is well known in Spain between chalkhill blues, Spanish chalkhill blues and Poloymmatus caelestissimus, and I do not yet feel confident enough to pronounce definitively on this group! The underside of the male forewing is distinctively chalky white. Females closely resemble female chalkhill blues.

I hope to revisit sites in Aragón where I have seen this species a little later in the year, when Provence chalkhill blue might be on the wing for comparison.