100 MISSOURI BOTANICAL GARDEN BULLETIN 
it. A native of Great Britain, it was cultivated by the 
Romans, but there is no record of it in America previous to 
its introduction in Connecticut in the early part of the 
eighteenth century. In 1835 the roots were taken from Ohio 
to Pigeon Prairie, in Michigan, where at the present time the 
peppermint industry has grown to large proportions. It is 
also cultivated extensively in England and in Saxony. 
The crop is usually cut in August and September, when 
the earliest flowers have developed but before the leaves have 
fallen. During favorable seasons a second crop is sometimes 
harvested in November. After cutting, the plants are eured 
in a manner similar to that for hay, then raked into wind- 
rows and taken to the still, where the oil is extracted. The 
average yield of oil is about twenty-five pounds per acre for 
the black mint, the variety now most extensively grown, 
although it may be as high as sixty pounds per acre and as 
low as ten pounds per acre. 
There are three recognized kinds of peppermint: the Amer- 
ican mint of New York (M. piperita), the black mint or black 
mitcham (M. piperita var. vulgaris), a more productive 
variety introduced from Mitcham, England, about 1889, and 
the white mint or white mitcham (M. piperita var.officinalis) 
which produces a superior grade of oil but with smaller yield. 
Other varieties of the genus include spearmint (M. spicata), 
pennyroyal (M. Pulegium), the popular name flea-bane sug- 
gesting its use, bergamot mint (M. citrata), round-leaved 
mint (M. rotundifolia), American wild mint (M. canadensis), 
and the Japanese mint (M. arvensis var. piperascens). 
In the early days efforts were made to obtain seed of varie- 
ties of mints which would produce the largest quantity of 
volatile oil of the strongest quality, it being recognized that 
cultivation had greatly improved the wild forms. Henry 
Dethicke, in the ‘‘Gardeners’ Labyrinth,’’ gives some curious 
advice to those who cannot procure cultivated plants: ‘‘Let 
him plant the seed of the wild mint, setting the sharper ends 
downwards whereby to tame and put away the wildness of 
them.’’ 
Another member of the mint family, though not belonging 
to the genus Mentha, is lavender (Lavendula vera). This is 
