390 WATER DOCK. 



the base, often a foot and a half in length, slightly toothed and 

 waved at the margin, rather glaucous, with strong channelled 

 petioles frequently a foot in length, subtended by a small tubu- 

 lar, scariose stipula, or ochrea ; the cauline leaves are gra- 

 dually smaller, and the uppermost are linear-lanceolate, acu- 

 minate, more entire at the margin, and tapering into short 

 petioles ; the veins of the larger leaves are very prominent, and 

 nearly at right angles with the midrib. The flowers are dis- 

 posed in close spurious whorls, subtended by scariose bracteae, 

 forming a sort of panicle ; each flower is pendulous on a 

 slender peduncle thickened at the apex. The calyx consists 

 of three small, ovate-oblong, acute, rather concave, erect, 

 glabrous sepals, slightly cohering at the base. The three 

 petals are ovate, obtuse, entire, greenish, veiny, longer than 

 the sepals, and enlarging over the fruit, are called valves. The 

 stamens are six, with short setaceous filaments tipped with 

 oblong two-lobed anthers. The germen is superior, trique- 

 trous, glabrous, supporting three very short setaceous styles 

 with pencilliform dependent stigmas. The fruit is a trique- 

 trous smooth nut, enclosed in the valves, which, at the period 

 of maturation, are large, ovate-deltoid, veined, entire or very 

 slightly waved at the margin near the base, and have each an 

 oblong, greenish white, or purplish tubercle, extending down 

 the middle. Plate 46, fig. 4, (a) ripe fruit, with the enlarged 

 petals or valves ; (b) pistil, magnified ; (c) nut ; (d) cluster of 

 flowers in the early period of growth ; (e) one of these flowers, 

 slightly magnified. 



This plant is commonly met with on the margin of rivers, 

 pools, and ditches, flowering in July and August. 



The origin of the generic name has been already explained. 

 The specific term, Hydrolapathum, is a compound of v$vf 9 

 water and hctiruQov, dock ; the latter being derived from tuna^u, 

 to evacuate, in allusion to the aperient qualities of some of the 

 species. Muntingius and some others have supposed that the 

 great Water-Dock is the ^Era,m>tn of Dioscorides, and the 

 Herba Britannka of Pliny. 



The great Water-Dock has been frequently confounded with 

 the Rumex aquaticus of Linnaeus, but this appears to be dis- 

 tinct, in having no tubercles on the enlarged reticulated petals, 

 and is similar in habit to the Curled Dock (R. crtspus). For 



