The Collaborative International Dictionary of English v.0.48:

Service \Serv"ice\, n., or Service \Serv"ice\ [Properly, the
   tree which bears serve, OE. serves, pl., service berries, AS.
   syrfe service tree; akin to L. sorbus.] (Bot.)
   A name given to several trees and shrubs of the genus
   Pyrus, as Pyrus domestica and Pyrus torminalis of
   Europe, the various species of mountain ash or rowan tree,
   and the American shad bush (see Shad bush, under Shad).
   They have clusters of small, edible, applelike berries.
   [1913 Webster]

   Service berry (Bot.), the fruit of any kind of service
      tree. In British America the name is especially applied to
      that of the several species or varieties of the shad bush
      (Amelanchier.)
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Juneberry \June"ber`ry\, n. (Bot.)
   (a) The small applelike berry of American trees of genus
       Amelanchier; -- also called service berry.
   (b) The shrub or tree which bears this fruit; -- also called
       shad bush, and shad tree.
       [1913 Webster]