568 
BRITISH PLANTS. 
rounded, and almost heart-shaped below ; and 
there are some others of less importance. 
Peppermint is a warm aromatic stimulant, and 
the most pleasant of all the mints. The leaves 
and upper part of the stems are the officinal 
parts ; they have a more penetrating smell 
than any of the others, and a much warmer 
pungent glowing taste, sinking, as it were, 
into the tongue. Water extracts the whole 
of the pungency by infusion, and elevates it 
in distillation. The officinal preparations are 
an essential oil, a simple water, and a spirit. 
The volatile oil is sometimes taken as an anti- 
spasmodic ; and it is what gives their flavour 
to peppermint lozenges. 
31. aquatica, Linnaeus. — "Water Mint. 
Stem erect ; leaves stalked, ovate, rounded 
below, serrate, uppermost ones like bracts, and 
shorter than the whorls; whorls fern, subglo- 
bose, capitate, the uppermost terminal ; calyx 
tubular, with triangular, awl-shaped teeth, 
hairy. A herbaceous perennial, growing two 
or three feet high, with fibrous roots, long 
creeping suckers, square, mostly hairy stems, 
and ovate, or elliptic-ovate leaves, rounded or 
tapering at the base ; the flowers are usually 
in whorls, but the uppermost head is always 
terminal ; they are produced in August and 
September ; the calyx is glandular, and clothed 
with hairs pointing upwards ; the corolla pur- 
plish, hairy on the outside. Found commonly j 
on the banks of rivers, and in watery places. 
31. citrata, Ehrhart (M. odorata, Sole), the 
Bergamot Mint, is regarded as being only a 
glabrous variety of this plant ; this furnishes 
a fragrant oil. 31. aquatica was once in 
repute as a stomachic and emmeuagogue. 
31. sativa, Linnaeus. — "Whorled hairy Mint. 
Stem erect ; leaves stalked, ovate or ellip- 
tical, serrate, upper ones similar, but smaller, 
all longer than the whorls ; whorls all distant, 
dense ; calyx bell-shaped, teeth triangular, 
lanceolate, acuminate. A herbaceous peren- 
nial, very variable in appearance, growing 
two feet or upwards in height, with fibrous 
roots, spreading suckers, square stems, and 
whorled inflorescence. Flowers in August 
and September. Found in wet places, not 
unfrequent. There are several varieties dis- 
tinguished : — vulgaris (31. sativa, Smith) 
has the calyx and flower-stalks hairy; rubra 
(31. rubra, Smith ; M. sativa, Sole) has the 
flower-stalks and lower part of the calyx 
glabrous, and the stem reddish ; gentilis ( M. 
gentilis, Smith) has the leaves nearly of the 
same size, stem green, glabrous, flower-stalks 
and lower part of calvx glabrous, with shorter 
triangular teeth ; acutifolia (31. acutifolia, 
Smith) has ovate lanceolate leaves, tapering to 
each end, and the flower-stalks and calyx 
hairy all over. 
M.arvensis, Linna?us. — Corn Mint. Stem 
erect ; leaves stalked, ovate or elliptical, ser- 
rate, upper ones similar and equally large; 
whorls distant ; calyx bell-shaped ; teeth tri- 
angular, as broad as long. A herbaceous 
perennial, growing upwards of a foot high, 
with fibrous roots, spreading suckers, square 
stems, smooth, sometimes hairy, and ovate 
acute leaves, sharply and somewhat unequally 
serrated ; the flowers are in whorls in the 
axils of the upper leaves, and are produced from 
June to September ; the corolla is pale pur- 
plish blue, generally hairy externally. Found 
in corn fields. There are two forms of this 
plant distinguished ; — vulgaris (31. arvensis, 
Smith), which has the leaves narrowed below; 
agrestis(3I. agrestis, Smith), which has leaves 
somewhat cordate below, upper ones nearly 
sessile. This plant is reputed to have the 
same medical properties as 31. aquatica and 
31. rotundifolia. The smell of the plant is 
not very agreeable, and has been compared to 
that of decayed cheese. 
* * Throat of calyx closed with hairs. 
31. Pulegi.um, Linna3us. — Penny-royal. 
Stem prostrate ; leaves stalked, elliptical 
obtuse, slightly crenate, all similar ; whorls all 
distant, globose, many flowered ; calyx tubular 
hispid. A herbaceous perennial, with trailing 
Mentlici Putegium. 
rooting stems, and small obtuse leaves, pro- 
fusely covered with small glandular dots. It 
forms a dense evergreen tuft, never rising 
more than a few inches high. The flowers 
are in distant whorls, large in proportion to 
the size of the leaves, light purple, nearly 
white ; produced in August and September. 
It is the smallest of all the British species of 
mint. Found in wet ditches and similar 
