The sub-units are called Flying Geese.
They can be put together in countless ways.
Google image on Flying Geese Quilts for more variations.
I'd never heard of Tree Everlasting - this listing shows the units have flattened tops, not pointed like flying geese.
http://cgi.ebay.com/ws/eBayISAPI.dll...WEdFTAPAg%253D
http://www.quilterscache.com/T/TreeE...tingBlock.html