The orchid with the yellow flowers is Psygmorchis pusilla, which was featured in More Pictures 1 in December, 1998. This is the second batch of flowers that it has produced since that time. It shares a branch with a bromeliad, Tillandsia bulbosa. Right behind the T. bulbosa is a branch with Pleurothallis tribuloides and T. filifera growing on it. The Pleurothallis has grown lots of orange-tipped aerial roots ever since it was placed in the vivarium. Both branches are held by wires to a nylon screw attached to the top of the vivarium. 

A small slab of cork hangs on the coconut fiber backing of the vivarium. A patch of live green moss growing on it keeps an Apendicula orchid nice and moist. Believe it or not, this orchid is in full bloom, but the flowers are so tiny you'd need a magnifying glass to see them well. 
 
All three orchids were purchased from Andy's Orchids, while the Tillandsias were from Black Jungle Terrarium Supply.