594 PHARMACEUTICAL BOTANY 
quadrangular, rarely cylindrical in outline. Leaves opposite, 
decussate, mainly petiolate; leaf margin nearly always serrate, 
dentate or crenate. Stems and leaves further characterized 
by the presence of glandular hairs containing aromatic volatile 
rca. guerregem Ol. These hairs, for the greater 
© 48. part, consist of a short one-celled 
_ stalk and a head (gland) of six or 
« cightcells. Inflorescence a raceme 
.. or spike of verticillasters (double 
_ dichasial cymes) or, as in the 
_ Ground Ivy, a reduced verticillas- 
_ ter. Flowers typically pentamer- 
| ous, rarely tetramerous; sepals five, 
_| synsepalous, ribbed and forming a 
_ tubular, regular or irregular bilabi- 
» ate (Scullcap, etc.) calyx whose 
upper lip is bifid and lower trifid; 
corolla of five to four gamopetalous 
ict: mB Fe petals, hypogynous, frequently two- 
_ Fic. 452.—Peppermint (Mentha lipped, the upper lip bifid, the 
sot hee wot fee ee lower trifid; stamens four, didyna- 
of eastern and central North Mous, rarely one pair alone fertile 
America. Note the opposite, petio- and the other pair reduced, in some 
late, ovate-oblong leaves with serrate : “ 
cases alm Be 
margins and the flowers which are ost or quite to disappear 
purple and borne on blunt spikes of ing point, as in the Sage (Salvia) 
verticillasters terminating the square and the Horsemint (M. onarda); 
stems. (Reproduced from U.S. Dept. pistil bicarpellate, embryologically 
aes Ae: Peat two-celled with two ovules in each 
cavity, becoming, at time of flowering, four-celled with one 
ovule in each cavity. Style embryologically terminal, but, upon 
opening of flower, deeply gynobasic, elongate, slender, with 
two stigmatic surfaces. Fruit four nutlets enclosing as many 
exalbuminous seeds. 
i 
OrrictAL Druc PART Usep BoraAnicAL Oricin Hasrrar 
Mentha Piperita Leaves and tops Mentha piperita Europe 
(Peppermint) 
Oleum. Menthz Volatile oil from Mentha piperita 
Piperita fresh aerial parts of 
flowering plant 
Europe 
