Peppermint 461
from the Latin piper, meaning pepper, alluding to its aromatic and pungent taste
(Tyler et al., 1988). There are three varieties of M. piperita L.: variety vulgaris Sole
or Mitcham mint, the most widespread throughout the world; variety sylvestris Sole
or Hungarian mint, and variety officinalis Sole. Two varieties of the species, black
mint (which has violet-coloured leaves and stems) and white mint (which has pure
green leaves) are under cultivation (Briggs, 1993; Bruneton, 1995; Leung and Foster,
1996; Wichtl and Bisset, 1994). The most extensively cultivated is the so-called
English or black mint, M. piperita officinalis rubescens Camus. This variety yields
more volatile oil than white mint (Masada, 1976).
The plant grows from 45 to 80 cm tall, resembling M. spicata closely and differing
in relatively long petiolated opposite lanceolate leaves and broader inflorescence.
The stem is quadrangular, channelled, purplish, somewhat hairy and branching towards
the top. The leaves are opposite, petiolate, ovate, sharply seriate, pointed, smoother
on the upper than on the under surface, and of a dark green colour, which is paler
beneath. The leaf lamina (4–14 cm) possesses hair and glandular trichomes on both
the surfaces. Usually the lower surface of leaves contain more glandular trichomes
than the upper surface. The inflorescence is verticillate. The flowers are small, purple,
and in terminal obtuse spikes, interrupted below, and cymosely arranged. Late in the
season, the growth of the lateral lower branches often gives to the inflorescence the
appearance of a corymb. The calyx is tubular, often purplish, furrowed, glabrous
below, and five-toothed, the teeth being hirsute. The corolla is purplish, tubular, with
its border divided into four segments, of which the uppermost is broadest, and notched
at its summit. The four short stamens are concealed within the tube of the corolla; the
style projects beyond it, and terminates in a bifid stigma. The presences of volatile
essential oils in the leaves and other parts of the plant gives the plant a very appealing
scent and fills the surrounding air with a pleasant aroma of mint.
28.2.2 Distribution and history of cultivation
Peppermint is found growing wild throughout Europe, North America and Australia
along stream banks and in moist wastelands, and is also cultivated under a number of
varieties, strains, or chemotypes (Trease and Evans, 1989). It has a long history of
cultivation in northern and southern temperate regions along stream banks and in
other moist areas. It was believed to be cultivated in ancient Egypt, although the
record of cultivation was known to be near London in 1750. In the late 1600s and
early 1700s it was first recognized as a distinct species by John Ray, a botanist. The
peppermint of commerce today is obtained mostly from cultivation in Bulgaria,
Greece, Spain, northern Europe, and the United States (BHP, 1996). The United
States is the leading producer of peppermint oil, especially in Washington, Oregon,
Idaho, Wisconsin, and Indiana (Tyler et. al., 1988).
Mint leaves have been used in medicine for several thousand years, according to
records from the Greek, Roman, and ancient Egyptian eras (Briggs, 1993; Evans,
1991). The origin of peppermint cultivation is disputed, though there is some evidence
that it was cultivated in ancient Egypt. Roman naturalist Pliny the Elder (ca. 23–79
C.E.) wrote of its uses by the Greeks and Romans. Peppermint was first recognized
as a distinct species by botanist John Ray in his Synopsis Stirpium Britannicorum
(second edition, 1696), and his Historia Plantarum (1704). It became official in the
London Pharmacopoeia in 1721 (Briggs, 1993; Tyler et al., 1988). Today, peppermint
leaf and/or its oil are official in the national pharmacopoeias of Austria, France,