The secret inner beauty that lives beneath a flower’s surface is etched like diaphanous butterfly wings in Steven Meyers’ “Eucalyptus.” A medical radiology technologist for 25 years, Meyers began experimenting with floral X-rays in 1975, now peruses the grocery store for new radiographic subjects. Diverging from the traditional landscapes that he originally photographed, Meyers entered the virtually unexplored world of X-ray photography, which reveals otherwise invisible textures, details and shadows through negatives, positives, and combinations of the two.