The Collaborative International Dictionary
Parella \Pa*rel"la\, Parelle \Pa`relle\, n. [Cf. F. parelle.] (Bot.)
A name for two kinds of dock ( Rumex Patientia and Rumex Hydrolapathum).
A kind of lichen ( Lecanora parella) once used in dyeing and in the preparation of litmus.
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.
Wikipedia
Rumex hydrolapathum Huds. (great water dock; water dock; giant water dock) is a species of perennial herbaceous plants in the genus Rumex native to fens and freshwater banks of Europe and Western Asia. It is the tallest species in the genus, with flowering stems attaining a height of up to . It is one of the small number of decaploid organisms, containing two hundred individual chromosomes.
Usage examples of "rumex hydrolapathum".
The Great Water Dock (Rumex Hydrolapathum), the largest of all the Docks, 5 to 6 feet high, is frequent on river banks.