Here in Colorado, January is a time of muted shades—tan grasses, soft yellow willows, maroon sedges, gray seedheads—and erratic weather. Highs in the 50s are immediately followed by snow or a sub-zero wind-chill. I was craving green leaves, bright colors, tropical humidity against my chapped skin. In the midst of suspended existence, I needed a fix of fecundity. So last Saturday, my husband and I paid a visit to the tropics. We drove to Broomfield, just west of Denver, home of the Butterfly Pavilion.