126 ORDER GYMNOSPERM1A. 



prevalence of the quinary division or addition of parts 

 in the flowers throughout the Dicotyledonous class of 

 plants. 



THE ORDER GYMNOSPERMIA 



is, in fact, the remaining Labi at je of the natural 

 method, not included in the 2d artificial class of Lin- 

 naeus. In all these plants a common resemblance is 

 obvious ; they are many of them aromatic, all of 

 them square-stemmed, and opposite-leaved ; generally 

 producing their flowers in whorls or axillary clusters 

 at the summit of the stem, brought often so near 

 together as to resemble a spike. They may be con- 

 veniently divided into 2 sections : in the first of which 

 divisions of genera 



The calyx is mostly 5-cleft, and nearly regular. 



The first of these genera, which commonly offers 

 itself in our Floras, and in nature by the banks of 

 streams and in low grounds, in flower about midsum- 

 mer, is the Teucrium, which you cannot mistake, as 

 it entirely wants the upper lip of the corolla, or rather, 

 it appears cleft, and the stamens will be found pro- 

 truded through the conspicuous fissure. We have 

 but 2 species which are common, both with ovate, 

 entire leaves ; in one inclining to lanceolate (T. cana- 

 dense) ; in the other to oblong, and above sessile 

 (T. virginicum). The flowers are brought together 

 so closely, as to form a spike. These species are very 

 nearly related, and, contrary to most of the European 

 ones, have little or no odor. 



The Isanthus, a peculiar American annual, deviates 

 very remarkably, as its name implies, from most 

 other Labiate, by the regularity of its 5-lobed (blue) 



