True leaves on Prickly-pear Cactus

What I thought was a bud on this Prickly-pear Cactus are apparently true leaves of the cactus, which soon wither and drop off. I thought it was rather attractive. Macro shot taken on June 5th, when a few of us spent the day botanizing The Nature Conservancy's land at Rosedale, near Drumheller, in the Badlands of Alberta. There were lots of these Prickly-pear cacti on the beautiful rolling hills, but not a single one of them was in bloom yet.