Rumex Hydrolapathum

from The Collaborative International Dictionary of English v.0.48

Parella \Pa*rel"la\, Parelle \Pa`relle\, n. [Cf. F. parelle.]
   (Bot.)
   (a) A name for two kinds of dock ({Rumex Patientia} and
       {Rumex Hydrolapathum}).
   (b) A kind of lichen ({Lecanora parella}) once used in dyeing
       and in the preparation of litmus.
       [1913 Webster]

from The Collaborative International Dictionary of English v.0.48

Water dock \Wa"ter dock`\ (Bot.)
   A tall, coarse dock growing in wet places. The American water
   dock is {Rumex orbiculatus}, the European is {Rumex
   Hydrolapathum}.
   [1913 Webster]

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