Anna correctly identified our mystery seeds from last week as being from a hackberry tree. These particular seeds came from the netleaf or canyon hackberry, Celtis reticulata.
Canyon hackberries are found along streams, washes, and in canyons throughout the West.
They are for the most part shrubby, small trees.
There are also netlike ridges on hackberry seeds, which is one way to recognize them.
Another good reason to grow netleaf hackberry trees is that they are the larval food of the hackberry emperor butterfly, Asterocampa celtis.
What kinds of hackberry trees grow where you live? What do you think of them?