Being in tropical Florida, I have access to the rare "Gunga Googa" tree, which has a round seed, hollow, about 1/4" diameter, with a flanged, open lip at top. Looks EXACTLY like a clay pot (just black wash, and drybrush, and its identical).
AND the "Bottle Brush" tree, which has a seed about 3/8", a perfect cylinder with open top, looks exactly like a wooden bucket or small barrel.
See the Old Mexico town I built for Murphy, its loaded with them. A couple on roofs, on window sills, against walls, etc really adds life.
Every year, this time, when the seeds fall, I do my give away. You want a manila envelope full of both seeds?
PM me and I send. (Just a way of helping others, at the cost of a stamp). Its not fair most of you live in Arctic regions and thus have no access to the wonderful tropical plants we get here.
I can also throw in fibre sections of our cabbage palm. Woven fibres, very fine count, that make GREAT roof thatching, gibeons (just wrap them around a section of dow rod, add dirt to top), walls for tropical huts, etc.
Shredded and hand pressed into a cylinder or square, it makes GREAT hay/straw/tinder to.
All the above last forever. They dont deteriorate.