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.
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.