I've been looking through my files of plants seen when in Argentina a few years ago and, over the past month, have posted messages on the bulbs seen. Here is another: http://www.flickr.com/photos/andrewrmw/5186636996/ It was taken in northern Argentina in a deep canyon through which a river flowed. The whole place was humid and on the nearly vertical rock walls grew many plants, notably cacti, begonias, bromeliads and ferns. In this shot the rebutia is R. jajoiana but I do not know what the unusual bulbous bloom is. Small pieces of debris from the canyon walls are noticeable. At first observation I even thought that with the humidity and lichens present it might be a moss ally! But, no, it is not. So, I call upon you experts of those parts to render advice. Andrew Wilson San Diego