the natural
order Labiatae, native of Europe and parts of Asia, found wild and
naturalized throughout the civilized world in strong, moist soil on the
borders of ponds and streams. Its square, prostrate stems, which readily
take root at the nodes, bear roundish-oval, grayish-green, slightly
hairy leaves and small lilac-blue flowers in whorled clusters of ten or
a dozen, rising in tiers, one above another, at the nodes. The seed is
light brown, oval and very small. Like most of its near relatives,
pennyroyal is highly aromatic, perhaps even more so than any other mint.
The flavor is more pungent and acrid and less agreeable than that of
spearmint or peppermint.

Ordinarily the plant is propagated by division like mint, or more rarely
by cuttings. Cultivation is the same as that of mint. Plantations
generally last for four or five years, and even longer, when well
managed and on favorable soil. In England it is more extensively
cultivated than in America for drying and for its oil, of which latter a
yield of 12 pounds to the acre is considered good. The leaves, green or
dried, are used abroad to flavor puddings and other culinary
preparations, but the taste and odor are usually not pleasant to
American and English palates and noses.

=Peppermint= (_Mentha piperita_, Linn.) is much the same in habit of
growth as spearmint. It is a native of northern Europe, where it may be
found in moist situations along stream banks and in waste lands. In
America it is probably even more common as an escape than spearmint.
Like its relative, it has long been known and grown in gardens and
fields, especially in Europe, Asia and the United States.

_Description._--Like spearmint, the plant has creeping rootstocks, which
rapidly extend it, and often make it a troublesome weed in moist ground.
The stems are smaller than those of spearmint, not so tall, and are more
purplish. They bear ovate, smooth leaves upon longer stalks than those
of spearmint. The whorled clusters of little, reddish-violet flowers
form loose, interrupted spikes. No seed is borne.

_Cultivation._--Although peppermint prefers wet, even swampy, soil, it
will do well on moist loam. It is cultivated like spearmint. In
Michigan, western New York and other parts of the country it is grown
commercially upon muck lands for the oil distilled from its leaves and
stems. Among essential oils, peppermint ranks first in importance. It is
a colorless, yellowish or greenish liquid, w