A lot of people use Spanish moss in shows as top dressing here in Florida. It can be pulled out of a lot of trees in my area - but a word of caution. Harvest it with insecticide soaked plastic gloves - put it directly into a plastic bag and Microwave the bag before you use it or aquirt a shot of insecticide into it. Spanish moss is usually infested with "Chiggers" or "Red Bugs" which burrow into the skin and leave whelts which itch terribly also hard to kill under the skin. From one who has had the unfortunate experience. It does make the displays look great.
Spanish moss