130 
CLASS DIANDEIA. 
first view, suppose the corolla to consist 
of several petals, but if we attempt to pull 
them out, they will all come off together, 
and we perceive there is but one piece, 
or that it is monopetalous."^ In flowers 
of one petal, the stamens generally adhere 
^o the corolla; where there are several 
petals, the stamens are mostly attached 
to the receptacle. In the lilac the two 
stamens are opposite, adhering to the 
corolla. The form in which the blossoms 
are crowded together, forming a large 
bunch, is called a thyrse. 
Fig. 129, a, repi-esents a flower of the lilac; at h is the same, cut lengthwise to 
show the two stamens. The lilac, although so common with us, is an exotic ; the 
species most cultivated are the vulgaris, which has heart-shaped leaves, and the 
persica, or Persian, with narrower leaves. The prim, or privet {Ligustrum), is 
found growing wild in some parts of New England ; though, in general, it is seen 
but little in the United States except when cultivated. It is planted for fences : 
as it grows rapidly, it soon becomes useful for this purpose, and with its green 
leaves and white flowers, gives to the farms an air of neatness and taste. 
The Sage (Salvia) on account of the form of the corolla be- 
longs to the natural family of the labiate flowers ; such plants 
are mostly of the class Didynamia, having /o'W stamens, two 
long and two short ; but in some cases the labiate flowers 
have but two stamens : this circumstance, according to the Lin- 
naean classification, separates them from their natural family. 
Two abortive stamens may be observed in this plant, and 
it should undoubtedly be placed, with other Labiate plants, 
in the class Didynamia. The species commonly cultivated is 
the officinalis, a shrub-like, perennial plant ; to this we give 
more particularly the name of sage. Another species of the 
same genus is the sdara, called Clarry ; this has larger and 
broader leaves than the common sage : it is cultivated for its 
medicinal properties. A very small plant called Enchanter's 
night-shade {Circoea, Fig. 129, d) may be found growing wild 
in shady places. It has a small white blossom, in the parts of 
which uniformity as to number may be observed ; it has two 
stamens, a corolla w4th two petals, a calyx with two sepals, cap- 
sule with two cells, each of which contains two seeds. 
168. Symmetry of structure observable in the plants de- 
scribed is now considered as a law of nature, and when 
not to be found the case is regarded as a departure from the 
* Gamopetalous (petals united) is the term now applied to such corollas, as it is found they are ia 
leality composed of different pieces cohering together. 
Fig. I'iO. 
''riia— Sage— Enchanter's night-sba(le,--168. Symmetry of structure. 
