Resized and compressed, but otherwise unretouched. I noticed these at a rest stop on the way home from our visit to McDonald Observatory and the Davis Mountains. This was in the middle of the desert, so the whole rest stop was pretty dried out. I was surprised to see something so bright at my feet and thought it was litter until I looked closer. To give some scale - the dry leaves around the flowers are from live oaks and are usually between 1 and 2 inches long.

UPDATE August 21, 2005 - this appears to be Nyctaginea capitata, commonly known as Devil's Bouquet or Scarlet Musk-Flower. From other sources, the names apparently refer to the plant's musky odor, which some people find unpleasant. It didn't occur to me to stick my nose into these, so I have no personal experience as to what they smell like.