=Botanical Origin=—See preceding article.
=History=—The flowers probably in the first line attracted the
attention of popular medicine in Germany, as we pointed out, page 390.
=Description=—_Arnica montana_ produces large, handsome, orange-yellow
flowers, solitary at the summit of the stem or branches. The involucral
scales of the capitulum (20 to 24) are of equal length, but are
imbricated, forming a double row. They are very hairy, the shorter
hairs being tipped with viscid glands. The receptacle is chaffy, ¼ of
an inch in diameter, with about 20 ligulate florets, and of tubular
a much larger number. The ligulate florets, an inch in length, are
oblong, toothed at the apex, and traversed by about 10 parallel veins.
The achenes are brown and hairy, crowned by pappus consisting of a
single row of whitish barbed hairs.
The receptacle is usually inhabited by a fly, _Trypeta arnicivora_
Löw[1444]; the Pharmacopœia Germania (1872) therefore ordered the
florets to be deprived of the involucre and receptacle—“flosculi a
peranthodio liberati.” From a chemical point of view the usefulness of
this direction may be doubted.
[1444] Figured in Nees von Esenbeck’s _Plantæ medicinales_, Düsseldorf,
ii. (1833) fol. 39.
Arnica flowers have a weak, not unpleasant odour; they were formerly
used in making the tincture, but as the British Pharmacopœia now
directs that preparation to be made with the root, they have almost
gone out of use in Great Britain.
=Chemical Composition=—The flowers appear to be rather richer in
arnicin than the root, and are said to be equal if not superior to it
in medicinal powers; yet the essential oil they contain is not the
same. It is obtained in but extremely small amount and has a greenish
or blue coloration. Hesse (1864) has proved that the flowers are devoid
of a peculiar volatile alkaloid which had been supposed to be present
in them.