344: POPULAR FIELD BOTANY. 
naked or hairy. Corolla nearly regular, divided into four, tube 
very short. 
Most of the species of this genus may be known by their 
strong scent, which resembles that of Mentha viridis, the 
common Mint of the garden. They are handsome, and grow 
principally in watery places. 
Mentua sytvestris. Horse Mint. Common in England 
on damp ground, and by the sides of rivulets. Leaves ob- 
long, very acute, unequally cut at the edges, downy,. and 
hoary underneath. Spikes of flowers purple, with small 
coloured leaves under them, and the calyx very hairy. 
Mentna uirsuta. Hairy Mint. Frequent on the banks 
of rivers and in marshes. A handsome plant, but varying 
much ; sometimes the pretty lilac flowers are in a head, 
sometimes whorled, and at others forming a spike. The 
leaves are heart-shaped, cut at the edge, hairy and stalked, 
and often much crisped. Calyx hairy. 
MeEntTHA ARVENSIS. Corn Mint. Found in corn-fields, 
and therefore preferring a drier situation than the other 
species. The smell is said to be like decayed cheese. 
The flowers are in whorls, and have a short and bell-shaped 
calyx clothed with spreading hairs. Leaves hairy, egg-shaped, 
and cut at the edges. 
