The DICT Development Group

  Sorrel \Sor"rel\, n. [F. surelle, fr. sur sour, fr. OHG. s?r
     sour. See Sour.] (Bot.)
     One of various plants having a sour juice; especially, a
     plant of the genus Rumex, as Rumex Acetosa, Rumex
     Acetosella, etc.
     [1913 Webster]
  
     Mountain sorrel. (Bot.) See under Mountain.
  
     Red sorrel. (Bot.)
     (a) A malvaceous plant ({Hibiscus Sabdariffa) whose acid
         calyxes and capsules are used in the West Indies for
         making tarts and acid drinks.
     (b) A troublesome weed ({Rumex Acetosella), also called
         sheep sorrel.
  
     Salt of sorrel (Chem.), binoxalate of potassa; -- so called
        because obtained from the juice of Rumex Acetosella, or
        Rumex Axetosa.
  
     Sorrel tree (Bot.), a small ericaceous tree ({Oxydendrum
        arboreum) whose leaves resemble those of the peach and
        have a sour taste. It is common along the Alleghanies.
        Called also sourwood.
  
     Wood sorrel (Bot.), any plant of the genus Oxalis.
        [1913 Webster]

  sorrel tree
      n 1: deciduous shrubby tree of eastern North America having
           deeply fissured bark and sprays of small fragrant white
           flowers and sour-tasting leaves [syn: sorrel tree,
           sourwood, titi, Oxydendrum arboreum]
      2: Australian tree with acid foliage [syn: sorrel tree,
         Hibiscus heterophyllus]