If there are more than five images, you can navigate through the gallery using the arrow buttons that appear to the right and left of the lightbox containing the thumbnail images.
Click on a thumbnail to display a large version of that image in an overlay
Move the mouse pointer over the large image to display an Info Box and additional navigation links "next" and "prev(ious)" for an alternate way to move through the gallery.
Access More Galleries from the corresponding Plant Profile Pages or use the Wallpaper Image Browser to see them all.