1. Rheum Rhapon'Ticum

Rheum Rhapon'Ticum. Asia Minor, Siberia, Russia. This is cultivated as pie-plant, the leaf-petioles being used, as they possess pleasant acidulous properties; this species is the source of the cultivated European rhizome, and that of Moravia (Austria), Hungary, England, and Banbury, which is usually less than half the size of official rhubarb, conical, harder, lighter color, more bitter and astringent, less gritty; contains rhapontin, C22H24O9.

2. R. undula'tum, R. compac'tum, R. Emo'di, R. austra'le, R. hyb'ridum. - All produce handsome, but smaller, less valuable, and lighter-colored rhizomes.

3. Ru'Mex Cris'Pus, Yellow Dock

Ru'Mex Cris'Pus, Yellow Dock. The dried root, official 1860-1900; Europe, N. America. Compact perennial springing from a yellow fusiform root, which penetrates far into the ground; stem rises annually 1-1.3 M. (3-4°) high; leaves lanceolate, smooth, margins strongly wavy-curled; flowers greenish, racemes. Root, 10-30 Cm. (4-120) long, 6-18 Mm. (1/4-3/4') thick, fusiform, deeply wrinkled, rusty-brown - internally whitish with reddish medullary rays; bark rather thick, fracture short; odor slight, peculiar; taste bitter, astringent; contains chrysophanic acid (rumicin, lapathin), nepodin, lapodin, tannin, calcium oxalate, starch. Astringent, alterative, tonic, laxative, antiscorbutic; similar to rhubarb and sarsaparilla; cutaneous eruptions, scorbutic manifestations, itch, scrofula, syphilis, hepatic congestion, dyspepsia, intermittents; leaves used as a laxative diet, and as spinach. Dose, gr. 15-60 (1-4 Gm.); fluidextract (diluted alcohol, xv-60 (1-4 Ml. (Cc.)); decoction and ointment also employed.

4. R. britan'nica, Water Dock. - The root, official 1820-1860-Europe, naturalized in N. America. Plant 1.6-2 M. (5-6°) high, leaves lanceolate, acute, transversely veined, obscurely crenate, .3-.6 M. (1-2°) long; root more astringent but physically and medicinally similar to R. crispus, with which it is often indiscriminately collected.

Fig. 101.   Rumex crispus.

Fig. 101. - Rumex crispus.

Fig. 102.   Polygonum Bistorta: rhizome, natural size.

Fig. 102. - Polygonum Bistorta: rhizome, natural size.

5. R. obtusifo'lius, Broad-leaved Dock. - The root, official 1820-1860. Europe, naturalized in N. America. Common obnoxious weed .6-1 M. (2-3°) high, leaves 15-30 Cm. (6-12') long, 7.5-10 Cm. (3-40 wide, sometimes red-veined, ovate, heart-shaped, downy, wavy margins, acuminate; roots similar to R. crispus, with which it is often indiscriminately collected, both alike medicinally. R. sanguin'eus, Red-veined Dock. - Leaf-veins and stems reddish; R. aqua'ticus, fruit smooth, both astringent. R. Acetosel'la, Field or Sheep Sorrel, contains acid potassium oxalate and tartaric acid, sour taste lost upon drying; refrigerant, diuretic, good diet in scurvy.