_Indian Hydrocotyle_, _Indian Pennywort_; F. _Bevilacqua_.
=Botanical Origin=—_Hydrocotyle asiatica_ L., a small creeping
herb,[1136] with slender jointed stems, common in moist places
throughout tropical Asia and Africa, ascending in Abyssinia to
elevations of 6,000 feet. It also occurs in America from South Carolina
to Valdivia, in the West Indies, the islands of the Pacific, New
Zealand, and Australia.
=History=—Hydrocotyle is called in Sanskrit _mandūka-parnī_, in Hindi
_khulakhudi_. The former name denotes various plants, but is thought
to refer in Susruta to the plant under notice (Dr. Rice). It was known
to Rheede[1137] by its Malyalim name of _Codagam_ (or _Kutakan_),
and also to Rumphius.[1138] It has been long used medicinally by the
natives of Java and of the Coromandel coast. In 1852, Boileau, a French
physician of Mauritius, pointed out its virtues in the treatment of
leprosy,[1139] for which disease it was largely tried in the hospitals
of Madras by Hunter[1140] in 1855. It has since been admitted to a
place in the _Pharmacopœia of India_.
[1134] See my paper on _Cucumis Colocynthis_ considered as a nutritive
plant in the _Archiv der Pharmacie_, 201 (1872) 235.—F. A. F.
[1135] Col. Grant, Botany of the Speke and Grant expedition, _Journ.
Linn. Soc._ xxix. pt. 2 (1873) 77.
[1136] Fig. in Bentley and Trimen. _Med. Plants_, pt. 24, 1877.
[1137] _Hort. Mal._ x. tab. 46.
[1138] _Herb. Amboin._ v. 169.
[1139] Bouton, _Med. Plants of Mauritius_, 1857. 73-83.
[1140] _Medical Reports_, Madras, 1855. 356.
=Description=[1141]—The peduncles and petioles are fasciculed; the
latter are frequently 2½ inches long; the peduncles are shorter and
bear a 3-or 4-flowered simple umbel with very short rays. The leaves
are reniform, crenate, ½ to 2 inches in longest diameter, 7-nerved,
glabrous, or when young somewhat hairy on the under side. The fruit
is laterally compressed, orbicular, acute on the back; the mericarps
reticulated, sometimes a little hairy, with 3 to 5 curved ribs; they
are devoid of vittæ. The main root is an inch or two long, but roots
are also thrown out by the procumbent stem.
When fresh, the herb is said to be aromatic and of a disagreeable
bitter and pungent taste; but these qualities appear to be lost in
drying.
=Chemical Composition=—An analysis of hydrocotyle has been made by
Lépine, a pharmacien of Pondicherry,[1142] who found it to yield a
somewhat peculiar body which he called _Vellarin_, from _Valālrai_,
the Tamil name of the plant, and regarded as its active principle.
Vellarin, which is said to be obtainable from the dry plant to the
extent of 0·8 to 1·0 per cent., is an oily, non-volatile liquid with
the smell and taste of fresh hydrocotyle, soluble in spirit of wine,
ether, caustic ammonia, and partially also in hydrochloric acid.
These singular properties do not enable us to rank vellarin in any
well-characterized class of organic compounds.
By exhausting 3 ounces of the dried herb with rectified spirit, we did
not obtain any thing like vellarin, but simply a green extract almost
entirely soluble in warm water, and containing chiefly tannic acid,
which produced an abundant green precipitate with salts of iron. With
caustic potash, neither the herb nor its extract evolved any nauseous
odour. The dried plant afforded Lépine 13 per cent. of ash.
=Uses=—As an alterative tonic, hydrocotyle is allowed to be of some
utility, but the power claimed for it by Boileau of curing leprosy is
generally denied. Dorvault[1143] regards it as belonging to the class
of narcotico-acrid poisons such as hemlock, but we see no evidence to
warrant such an opinion. Besides being administered internally, it is
sometimes locally applied in the form of a poultice. Boileau says that
the entire plant is preferable to the leaves alone.[1144]
=Substitutes (?)=—_H. rotundifolia_ Roxb., another species common in
India, may be known from _H. asiatica_ by having 10 or more flowers
in an umbel and much smaller fruits. The European _H. vulgaris_ L.,
easily distinguishable from the allied tropical species just described,
by having its leaves orbicular and peltate (not reniform), is said to
possess deleterious properties.
[1141] Drawn up from Indian specimens.
[1142] _Journ. de Pharm._ xxviii. (1855) 47.
[1143] _L’Officine_ (1872) 554.
[1144] It is probably by oversight that the _leaves alone_ are ordered
in the _Pharmacopœia of India_.