502 Handbook of herbs and spices
31.1 Introduction
Mentha spicata L., one of the total of about 25 species of the genus Mentha (Lamiaceae)
is indigenous to northern England and is known by several names such as nature
spearmint, brown mint, garden mint, lady’s mint, sage of Bethlehem, etc. The plant
is now grown practically all over the world as an important spice plant and a natural
source of carvone rich essential oil which is widely traded in the world. The major
spearmint growing countries are the USA, Russia, Germany, Australlia and China.
The world market for spearmint oil is approximately 1500 t/year (Peterson and
Bienvenu, 1998).
Following Husain et al. (1988) and Patra et al. (2001) spearmint can be botanically
described as follows. Like other mints, M. spicata is perennial, propagating mostly
by underground stolons from which a 50–56 cm aerial stem arises. Erect ascending
branches, each measuring 30–60 cm develop from each stem. Leaves are sessile or
nearly so, smooth, lanceolate or ovate-lanceolate, sharply serrate, smooth above and
glandular below, acute apex and up to 7.0 cm ¥ 2.0 cm in size. The leaves possess a
characteristic smell and pungent taste, lacking a cooling after-effect in contrast to
that of peppermint and Japanese mint. Flowers are sharply pointed, long and narrow
and rightly called spearmint. Calyx teeth are hirsute or glabrous and corolla is about
3 mm long and whitish purple in colour. M. spicata is a natural tetraploid (2n = 48)
that originated by chromosome doubling of hybrids between the two closely related
interspecific diploids M. longifolia (2n = 24) and M. suaveolens (2n = 22) (Harley
and Brighton, 1977; Tyagi et al., 1992).
31 Spearmint..................................................................................................
N. K. Patra and B. Kumar, Central Institute of Medicinal and Aromatic
Plants, India