_Dandelion Root_, _Taraxacum Root_; F. _Pissenlit_; G.
_Löwenzahnwurzel_.
=Botanical Origin=—_Taraxacum officinale_ Wiggers _T. Dens-leonis_
Desf., _Leontodon Taraxacum_ L., a plant of the northern hemisphere,
found over the whole of Europe, Central and Northern Asia, and
North America, extending to the Arctic regions. It varies under a
considerable number of forms, several of which have been regarded as
distinct species. In many districts it is a troublesome weed.
=History=—Though the common Dandelion is a plant which must have been
well known to the ancients, no indubitable reference to it can be
traced in the classical authors of Greece and Italy; it is thought
that ἀθάκη of Theophrast and others means it. The word _Taraxacum_ is
however usually regarded as of Greek origin;[1445] we have first met
with as _Tarakhshagun_ in the works of the Arabian physicians, who
speak of it as a sort of _Wild Endive_. It is thus mentioned by Rhazes
in the 10th, and by Avicenna in the 11th century.
The name _Dens Leonis_, an equivalent of which is found in nearly
all the languages of Europe, is stated in the herbal of Johann von
Cube[1446] to have been bestowed on this plant by one Wilhelm, a
surgeon, who held it in great esteem; but of this personage and of the
period during which he lived we have sought information in vain, and we
may remember that Dens Leonis (“Dant y Llew”) is already met with in
the Welsh medicine of the 13th century.[1447]
Dandelion was also much valued as medicine in the time of Gerarde and
Parkinson, and is still extensively employed.
=Collection=—In England, taraxacum root is considered to be in
perfection for extract in the month of November, the juice at that
period affording an ampler and better product than at any other.
Bentley contends that it is more bitter in March, and most of all in
July, and that at the former period at least it should be preferred.
=Description=—The root is perennial, and tapering, simple, or slightly
branched, attaining in a good soil a length of a foot or more, and half
an inch to an inch in diameter. Old roots divide at the crown into
several heads. The root is fleshy and brittle; externally of a pale
brown, internally white, and abounding in an inodorous milky juice of
bitter taste. It shrinks very much in drying, losing in weight about 76
per cent.[1448]
Dried dandelion root is half an inch or less in thickness, dark
brown, shrivelled with wrinkles running lengthwise often in a spiral
direction; when quite dry, it breaks easily with a short corky
fracture, showing a very thick white bark, surrounding a woody column.
The latter is yellowish, very porous, without pith or rays. A rather
broad but indistinct cambium-zone separates the wood from the bark,
which latter exhibits numerous well-defined concentric layers. The root
has a bitterish taste.
=Microscopic Structure=—On the longitudinal section, especially
in a tangential direction, the brownish zones are seen to contain
laticiferous vessels, only about 2 mkm. in diameter. These traverse
their zones in a vertical direction, giving off numerous lateral
branches, which however remain always confined to their zone. Within
each of these zones, the lacticiferous vessels form consequently an
anastomosing net. We may say that the root is thus vertically traversed
by about 10 to 20 concentric rings of lacticiferous vessels.[1449] They
may be made beautifully evident by means of anilin-blue, with which
a thin longitudinal section of the fresh root may be moistened. The
root must be allowed to partially dry, but only till the milky juice
coagulates; the thin slice then energetically absorbs the colouring
matter.[1450]
[1445] Perhaps from τράζυνον or τρόξμνον signifying _Wild Lettuce_;
according to some, from τάραξις, a disease of the eye which the plant
was used to cure, or from the verb τάρασσω, _I disturb_.
[1446] _Herbarius zu teutsch und von aller handt kreuteren_, Augspurg,
1488. cap. clii.
[1447] The _Physicians of Myddvai_, 284 (see Appendix).
[1448] Thus 5496 lb. of the washed root afforded of dry only 1277
lb., or 23·2 per cent.—Information communicated by Messrs. Allen and
Hanburys, London.
[1449] For further particulars about them, see Vogl, _Sitzungsber.
der Wiener Akademie_, vi. (1863) 668 with plate; Hanstein,
_Milchsaftgefässe und verwandte Organe der Rinde_, Berlin, 1864. 72.
73. pl. ix.
[1450] The reader who is not familiar with this process may refer to a
paper by Pocklington in _Pharm. Journ._ April 13, 1872. 822.
The tissue of the dried root is loaded with inulin, which does not
occur in the solid form in the living plant. The woody part of
taraxacum root is made up of large scalariform vessels accompanied by
parenchymatous tissue, the former much prevailing.
=Chemical Composition=—The fresh milky juice of dandelion is bitter
and neutral, but it soon acquires an acid reaction and reddish brown
tint, at the same time coagulating with separation of masses of what
has been called by Kromayer (1861), _Leontodonium_. This chemist, by
treating this substance with hot water, obtained a bitter solution
yielding an active (?) principle to animal charcoal, from which it was
removed by means of boiling spirit of wine. After the evaporation of
the alcohol, Kromayer purified the liquid by addition of basic acetate
of lead, saturation of the filtered solution with sulphuretted hydrogen
and evaporation to dryness. The residue then yielded to ether an acrid
resin, and left a colourless amorphous mass of intensely bitter taste,
named by Kromayer _Taraxacin_. Polex (1839) obtained apparently the
same principle in warty crystals; he simply boiled the milky juice with
water and allowed the concentrated decoction to evaporate.
The portion of the “_Leontodonium_,” not dissolved by water, yields to
alcohol a crystalline substance, Kromayer’s _Taraxacerin_, C₈H₁₆O. It
resembles lactucerin and has in alcoholic solution an acrid taste. How
far the medicinal value of dandelion is dependent on the substances
thus extracted, is not yet known.
Dragendorff (1870) obtained from the root gathered near Dorpat in
October and dried at 100° C., 24 per cent. of _Inulin_ and some sugar.
The root collected in March from the same place yielded only 1·74 per
cent. of inulin, 17 of uncrystallizable sugar and 18·7 of _Levulin_.
The last named substance, discovered by Dragendorff, has the same
composition as inulin, but dissolves in cold water; the solution tastes
sweetish, and is devoid of any rotatory power. Inulin is often to be
seen as a glistening powder when extract of taraxacum is dissolved in
water.
T. and H. Smith of Edinburgh (1849) have shown that the juice of the
root by a short exposure to the air undergoes a sort of fermentation
which results in the abundant formation of _Mannite_, not a trace of
which is obtainable from the perfectly fresh root. Sugar which readily
underwent the vinous fermentation was found by the same chemists in
considerable quantity.
The leaves and stalks of dandelion (but not the roots) were found by
Marmé (1864) to afford the _Inosite_, C₆H₁₂O + 2 OH.
The root collected in the meadows near Bern immediately before
flowering, carefully washed and dried at 100° C., yielded us 5·24 per
cent. of ash, which we found to consist of carbonates, phosphates,
sulphates, and in smaller quantity also of chlorides.
=Uses=—Taraxacum is much employed as a mild laxative and tonic,
especially in hepatic disorders.
=Adulteration=—The roots of _Leontodon hispidus_ L. (Common Hawkbit)
have occasionally been supplied by fraudulent herb-gatherers in place
of dandelion. Both plants have runcinate leaves, but those of hawkbit
are hairy, while those of dandelion are smooth. The (fresh) root of the
former is tough, breaking with difficulty and rarely exuding any milky
juice.[1451]
The dried root of dandelion is exceedingly liable to the attacks of
maggots, and should not be kept beyond one season.