_Radix Iridis Florentinæ_; _Orris Root_; F. _Racine d’Iris_; G.
_Veilchenwurzel_.
=Botanical Origin=—This drug is derived from three species of _Iris_,
namely:—
1. _Iris germanica_ L., a perennial plant with beautiful large deep
blue flowers, common about Florence and Lucca, ascending to the region
of the chestnut. It is also found dispersed throughout Central and
Southern Europe, and in Northern India and Morocco; and is one of the
commonest plants of the gardens round London, where it is known as the
_Blue Flag_.
2. _I. pallida_ Lam., a plant differing from the preceding by flowers
of a delicate pale blue, growing wild in stony places in Istria. It is
abundant about Florence and Lucca in the region of the olive, but is a
doubtful native.
3. _I. florentina_ L., closely allied to _I. pallida_, yet bearing
large white flowers, is indigenous to the coast region of Macedonia
and the south-western shores of the Black Sea, Hersek, in the Gulf
of Ismid, and about Adalia in Asia Minor. It also occurs in the
neighbourhood of Florence and Lucca, but in our opinion only as a
naturalized plant.[2455]
These three species, but especially _I. germanica_ and _I. pallida_,
are cultivated for the production of orris root in the neighbourhood of
Florence. They are planted on the edges of terraces and on waste, stony
places contiguous to cultivated ground. _I. florentina_ is seldom found
beyond the precincts of villas, and is far less common than the other
two.
=History=—In ancient Greece and Rome, orris root was largely used in
perfumery; and Macedonia, Elis, and Corinth were famous for their
unguents of iris.[2456] Theophrastus and Dioscorides were well
acquainted with orris root; the latter, as well as Pliny, remarks that
the best comes from Illyricum, the next from Macedonia, and a sort
still inferior from Libya; and that the root is used as a perfume and
medicine. Visiani[2457] considers that _Iris germanica_ is the Illyrian
iris of the ancients, which is highly probable, seeing that throughout
Dalmatia (the ancient Illyricum) that species is plentiful, and _I.
florentina_ and _I. pallida_ do not occur. At what period the two
latter were introduced into Northern Italy we have no direct evidence,
but it was probably in the early middle ages. The ancient arms of
Florence, a white lily or iris on a red shield,[2458] seem to indicate
that that city was famed for the growth of these plants. Petrus de
Crescentiis[2459] of Bologna, who flourished in the 13th century,
mentions the cultivation of the _white_ as well as of the purple iris,
and states at what season the root should be collected for medicinal
use.
But the true Illyrian drug was held to be the best; and Valerius
Cordus[2460] laments that it was being displaced by the Florentine,
though it might easily be obtained through the Venetians.
[2455] From observations made at Florence in the spring of 1872, I
am led to regard the three species here named as quite distinct. The
following comparative characters are perhaps worth recording:—
_I. germanica_—flower-stem scarcely 1½ times as tall as leaves; flowers
more crowded than in _I. pallida_, varying in depth of colour but never
pale blue.
_I. pallida_—bracts brown and scariose; flower-stem twice as high as
leaves.
_I. florentina_—bracts green and fleshy; flower-stem short as in _I.
germanica_; is a more tender plant than the other two, and blossoms a
little later.—D. H.
[2456] For further information, consult Blümner, _Die gewerbliche
Thätigkeit der Völker des klassischen Alterthums_, 1869. 57. 76. 83.
[2457] _Flora Dalmatica_, i. (1842) 116.
[2458] Dante, _Divina commedia_, cant. xvi.
[2459] _De omnibus agriculturæ partibus_, Basil. 1548. 219.
[2460] _Dispensatorium_, Norimb. 1529. 288.
Orris root mixed with anise was used in England as a perfume for linen
as early as 1480 (p. 311), under which date it is mentioned in the
_Wardrobe Accounts_ of Edward IV.
All the species of iris we have named were in cultivation in England in
the time of Gerarde,—that is, the latter end of the 16th century. The
starch of the rhizome was formerly reckoned medicinal, and directions
for its preparation are to be found in the _Traicté de la Chymie_ of Le
Febvre, i. (1660) 310.
=Production=—The above-mentioned species of iris are known to the
Tuscan peasantry by the one name of _Giaggiolo_. The rhizomes are
collected indiscriminately, the chief quantity being doubtless
furnished by the two more plentiful species, _I. germanica_ and _I.
pallida_. They are dug up in August, are then peeled, trimmed,
and laid out in the sunshine to dry, the larger bits cut off being
reserved for replanting. At the establishment of Count Strozzi,
founded in 1806 at Pontasieve near Florence, which lies in the midst
of the orris district, the rhizomes, collected from the peasants
by itinerant dealers, are separated into different qualities, as
_selected_ (_scelti_) and _sorts_ (_in sorte_), and are ultimately
offered in trade either entire, or in small bits (_frantumi_),
parings (_raspature_), powder (_polvere di giaggiolo o d’ ireos_), or
manufactured into orris peas.
The growing of orris is only a small branch of industry, the crops
being a sort of side-product, but it is nevertheless shared between
the tenant and landowner as is usual on the Tuscan System of
husbandry.[2461]
[2461] Groves, _Pharm. Journ._ iii. (1872) 229.—We have also to thank
him for information communicated personally.
In the mountainous neighbourhood of Verona, the rhizomes of _Giglio
celeste_ or _Giglio selvatico_, _i.e._, Iris germanica, are collected
and chiefly brought to the small places of Tregnano and Illasi,
north-east of Verona. The peasants distinguish the selected long roots
(_radice dritta_), the knotty roots (_radice groppo_) which are used
for the issue-peas, and the fragments (_scarto_) employed in perfumery.
Some orris root is also exported from Botzen in southern Tyrol.
=Description.=—The rootstock is fleshy, jointed and branching,
creeping horizontally near the surface of the ground. It is formed in
old plants of the annual joints of five or six successive years, the
oldest of which are evidently in a state of decay. These joints are
mostly dichotomous, subcylindrical, a little compressed vertically,
gradually becoming obconical, and obtaining a maximum size when about
three years old. They are 3 to 4 inches long and sometimes more than
2 inches thick. Those only of the current year emit leaves from their
extremities. The rhizome is externally yellowish-brown, internally
white and juicy, with an earthy smell and acrid taste. By drying, it
gradually acquires its pleasant violet odour, but it is said not to
attain its maximum of fragrance until it has been kept for two years.
We have carefully compared with each other the fresh rhizomes of the
three species under notice, but are not able to point out any definite
character for distinguishing them apart.
Dried orris root as found in the shops occurs in pieces of 2 to 4
inches long, and often as much as 1¼ inches wide. A full-sized piece
is seen to consist of an elongated, irregularly subconical portion
emitting at its broader end one or two (rarely three) branches which,
having been cut short in the process of trimming, have the form of
short, broad cones, attached by their apices to the parent rootstock.
The rootstock is flattened, somewhat arched, often contorted, shrunken
and furrowed. The lower side is marked with small circular scars,
indicating the point of insertion of rootlets. The brown outer bark
has been usually entirely removed by peeling and paring; and the dried
rhizome is of a dull, opaque white, ponderous, firm and compact. It has
an agreeable and delicate odour of violets, and a bitterish, rather
aromatic taste, with subsequent acridity.
A sort of orris root which has been dried without the removal of the
outer peel, is found under the name of _Irisa_ in the Indian bazaars,
and now and then in the London market. It is, we suppose, the produce
of _Iris germanica_ L. (_I. nepalensis_ Wall.), which, according to
Hooker, is cultivated in Kashmir. Orris root of rather low quality
is now often imported from Morocco; it is obtained, we believe,
exclusively from _I. germanica_.
=Microscopic Structure=—On transverse section, the white bark about
2 mm. broad, is seen to be separated by a fine brown line from the
faintly yellowish woody tissue. The latter is traversed by numerous
vascular bundles, in diffuse and irregular rings, and exhibits here
and there small shining crystals of oxalate of calcium. It is made up
uniformly of large thick-walled spherical porous cells, loaded with
starch granules, which are oval, rather large and very numerous; prisms
of calcium oxalate are also visible. The latter were noticed already by
one of the earliest microscopic observers, Anton van Leeuwenhoek, about
the year 1716. The spiral vessels are small and run in very various
directions. The foregoing description is applicable to any one of the
three species we have named.
=Chemical Composition=—When orris root is distilled with water, a
crystalline substance, called _Orris Camphor_, is found floating on
the aqueous distillate. This substance, which we first obtained from
the laboratory of Messrs. Herrings & Co. of London, is yielded, as we
learn from Mr. Umney, to the extent of 0·12 per cent.—that is to say, 3
cwt. 3 qrs. 23 lb. of rhizome afforded of it 8½ ounces.[2462] Messrs.
Schimmel & Co. of Leipzig also presented us with the same substance, of
which they obtain usually 0·60 to 0·80 per cent. Orris camphor has the
exquisite and persistent fragrance of the drug; we have proved[2463]
that this presumed stearoptene or camphor of orris root consists of
_myristic acid_, C₁₄H₂₈O₂ (see page 508), impregnated with the minute
quantity of essential oil occurring in the drug. The oil itself would
appear not to pre-exist in the living root, but to be formed on drying
it.
By exhausting orris root with spirit of wine, a soft brownish resin
is obtained, together with a little tannic matter. The resin has a
slightly acrid taste; the tannin strikes a green colour with persalts
of iron.
=Commerce=—Orris root is shipped from Leghorn, Trieste and
Mogador,—from the last named port to the extent in 1876 of 834
cwt.[2464] There are no data to show the total imports into Great
Britain. France imported in the year 1870 about 50 tons of orris root.
=Uses=—Frequently employed as an ingredient in tooth-powders, and in
France for making issue-peas; but the chief application is as a perfume.
[2462] The produce of some previous operations, in which 23 cwt. of
orris was distilled, afforded but little over one-tenth per cent.
[2463] _Pharm. Journ._ vii. (1876) 130.
[2464] _Consular Reports_, 1876. 1416.