Mulberry Trees are common in the eastern half of the US. They produce a lot of berries and the birds love them.
Mulberries have a mild flavor. You can bake with them.
The trees are cultivated as well as wild.
The berries can be dark purple, red or white. They are messy trees when the berries fall to the ground.

All of the pictures are from Wikimedia Commons.

Male flower  by, Meneerke bloem.518px-Morus_nigra_male_flowers Meneerke boem WCFemale flower  by, J.J. Harrison.

Black_Mulberry_Female_Flowers JJ Harrison WCMulberry tree  by, Reneman.

400px-Maulbeerbaum_Morus_in_Bulgarien_06-2012 Reneman WCA weeping Mulberry tree in Istanbul, Turkey  by, Ugur Basak.

400px-Morus_alba_Pendula Ugaur Basak WCA Mulberry hedge  by, Daniel Fuchs.

Daniel_Fuchs.CC-BY-SA.Morus_nigra.Hedge Daniel Fuchs WCDark purple mulberries by B navez.

640px-Morus_alba_fruits B navez WCRed mulberry  by, Fredico A. Quitao.

Amoraselvagem Fredrico A Quitao WCThis last picture is of white mulberries  by, Daniel Fuchs.

640px-Daniel_Fuchs.CC-BY-SA.Morus_alba.1 Daniel Fuchs WC