This image shows the rare and beautiful blossom of the desert finger cactus, apparently more commonly known today as the Lady Finger Cactus, common in the desert areas northeastern Mexico and the Rio Grande Valley.
Selithco True Color from Ektachrome
There is no description on the back of the card. The colors of the flower can vary somewhat but the shape and pattern of flower and colors is consistent.
This card likely dates from the 1950s.