Source : Webster's Revised Unabridged Dictionary (1913)

Oso-berry \O"so-ber`ry\, n. (Bot.)
   The small, blueblack, drupelike fruit of the {Nuttallia
   cerasiformis}, a shrub of Oregon and California, belonging to
   the Cherry tribe of {Rosace[ae]}.

Source : WordNet®

Rosaceae
     n : a large family of dicotyledonous plants of order Rosales;
         have alternate leaves and five-petaled flowers with
         numerous stamens [syn: {family Rosaceae}, {rose family}]