RUMEX HYDROLAPATHUM. ORD. XL. Oleracee. 6459 
these are very large, ovate, pointed, slightly notched towards the 
base, and furnished with an oblong grain, extending down the 
middle of each valve: the seed is solitary, ovate, triangular. It is 
a native of England, growing in ditches, pools, and rivers, and 
flowers in July and August. 
The Hydrolapathum of the Edinburgh Pharmacopeeia is referred 
to the R. aquaticus of Linnzus, which is supposed to be a different 
species from the Hydrolapathum of Mr. Hudson,* though the same 
synonyms are ascribed to both. The plant here represented, which 
was found in the river Rodon, near Woodford Bridge, by having 
toothed valves, does not agree with the specific characters given by 
either of these authors; but it seems to correspond exactly with the 
description of it subjoined by Dr. Withering.” 
The root, which is the part of this plant directed for medicinal 
use, has a strong austere taste, and readily strikes a black colour to 
a solution of ferrum vitriolatum, and yields its active matter both 
to water and to rectified spirit. 
Many of the Lapatha‘ were formerly officinal herbs, of which 
the Water Dock has been esteemed to be the most efficacious, and 
by the Edinburgh College is still retained in the Materia Medica: 
the leaves, which manifest considerable acidity, are said to possess 
a laxative quality, and have therefore been used to obviate costive- 
ness: the roots are stronghy astringent, and have been much 
employed both externally and internally for the cure of scurvy ;* 
especially when the gums are spongy, and frequent hemorrhages 
supervene. It is also recommended in various other cutaneous 
* dn: Cs Sima 
© From Aaragw, evacuo aagrw, idem. Alston. 
Si dura morabitur alvus, 
Mitulus & viles pellent obstacula conche oe 
Et Lapathi brevis herba. Honar. Sav. 4. lib. 2. v. 27. 
« Linneus speaks highly of its use. Vide Amen. vol. 4. p. 38. Flor. Suec. p. 
118. And in Lind’s Treatise on the Scurvy, p. 264. 
