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IRIS. U.S. N. F. ORRIS [Orris Root]
USD 1926
Compiled by Ivor Hughes

" Orris is the rhizome of Iris florentina Linne, Iris germanica Linne, or Iris pallida Lamarck (Fam. Iridaceae), freed from the roots, peeled and dried. Orris contains not more than 1 per cent, of foreign organic matter." N. F.

In all the species belonging to this genus, so far examined, the roots are more or less acrid, and possessed of cathartic and emetic properties. In Europe, Iris foetidissima L., I. pseudacorus L., and I. tuberosa L. have at various times been admitted into use, in addition to those here described.

The three species recognized, under the title " Iris," by the N. F. are valued rather for their pleasant odor than for their cathartic properties. The Iris versicolor is described in the succeeding article. Iris Germanica, commonly known as Fleur-de-Lys, is a perennial herb with dark blue or purplish flowers, native to central and southern Europe, but extensively cultivated as an ornamental plant in the United States and has become sparingly naturalized in Virginia. It is cultivated on a commercial scale in Italy, especially in the neighborhood of Verona, and also in Morocco. I. pallida, Lam. which is a native of the eastern Mediterranean countries, has pale bluish flowers. The rhizomes of these two species constitute what is known as Verona Orris. The Florentine orris is from the I. Florentina L. It has large white flowers and is of about the same distribution as the I. pallida. Its rhizome is generally the most fragrant although it is less widely cultivated than the other two species.

The rhizomes of these three species resemble one another so closely that it is often impossible to distinguish between them. They are gathered usually in the late summer from plants two or three years old and dried in the sun. The fresh rhizomes are without odor and have an acrid taste, but during the process of drying they lose much of their acridity and develop the characteristic fragrance. The Florentine variety is usually lighter in color and more pronounced in odor than the Veronese and also more carefully peeled. The commercial supplies of orris root come to the U. S. A. from Leghorn, Italy, and to a lesser extent from Mogador, Morocco.

Description and Physical Properties. " Unground Orris.� In pieces of various forms and sizes, usually jointed and branched, from 5 to 10 cm. long and from 1.5 to 3 cm. wide, rounded or flattened, with knotty enlargements; under surface with numerous root scars, the upper with leaf scars; externally yellowish white; internally light yellow; fracture hard, rough and at times mealy, showing a narrow cortex, a distinct endodermis and a large stele with numerous vascular bundles, especially near the endodermis. Odor fragrant, resembling that of violet flowers; taste slightly aromatic, bitterish, somewhat irritating.

" Structure.� Cortex composed mostly of starch-bearing parenchyma, the cells with thickened, porous walls and intercellular spaces within which occur large prisms of calcium oxalate which are also found in certain parenchyma cells with suberized walls; a distinct endodermis of collenchyma-like cells containing starch; a large central cylinder composed of starch-containing parenchyma with concentric vascular bundles irregularly placed throughout, the latter being most numerous near the endodermis.

"Powdered Orris.� Light yellow. Parenchyma cells of the cortex and central cylinder filled with characteristic starch grains, the latter oval, rounded at one end and flattened at the other, some curved or with irregular protuberances, mostly single, from 0.020 to 0.050 mm. in length and with an X-shaped cleft in the large rounded end of the grain, two of the fissures extending in the form of a horseshoe toward the small end of the grain; elements of vascular bundles, with tracheae showing spiral, annular, scalariform or reticulate markings, the tracheae from 0.010 to 0.025 mm. in width; calcium oxalate in prisms up to 0.500 mm. in length and 0.030 mm. in width." N. F.

Orris root contains much starch, a bitter and acrid fixed oil or soft resin and a crystallizable volatile oil. According to Landerer (A. Pharm., Ixv, p. 302), the acrid principle is volatile and separates in the form of a stearopten from �water distilled from the root. By distillation with steam the root yields about 0.1 or 0.2 per cent, of a semi-solid aromatic substance known as oil of orris or powder of orris. Fliickiger (A. J. P., 1876, 411; 1885, p. 133) has shown that this consists chiefly of myristic acid containing a small amount of the true odorous principle. The myristic acid, however, seems not to pre-exist in the orris root, but is probably liberated from a fat by the influence of the steam. The fragrance of the root has been shown by Tiemann to be due to irone (C₁₃H₂₀-0) which is a methyl ketone isomeric with ionone. In attempting its synthesis, Tiemann prepared an isomeric compound pseudoionone which however did not possess a pleasant odor but could be changed into ionone which has the

violet-like odor. This complex ketone is now manufactured synthetically for use in perfumery, lonone, of commerce, is a mixture of alpha and beta isomers which have been successfully separated. Alpha ionone has a sweet penetrating odor resembling orris while beta ionone is said to more closely resemble the violet odor.

Uses.� In large doses, orris root is cathartic and emetic and was formerly employed as a medicine. At present it is valued chiefly for its agreeable odor. It is occasionally chewed to conceal an offensive breath and enters into the composition of tooth powders.

Off. Prep.� Species Pectorales, N. F. (see the NF in the site library)

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