Longwood Gardens' Orchid Extravaganza

I had been meaning to walk around Longwood Gardens with my camera for months--I missed the chrysanthemums in fall and the holiday lights--but thanks to a great deal from Groupon I got to see the orchid show. Thousands of orchids in countless varieties were worked into the exhibit areas in the Conservatory, and the usual orchid room was full of colorful specimen. I am no orchid expert and wouldn't attempt to grow them, but I can shoot them with the Nikon...I LOVE the unusual color on these:

How do these know to form a perfect sphere?

Is this one my favorite? I'm not sure.