CLASS GTNANDEIA. 
class are poisonous ; for though milky plants are generally so, those of this class are 
exceptions. The lettuce contains a narcotic principle, and opium may be made 
from it. The dandelion, thoroughwort, chamomile, and wormwood, with many 
other plants of tliia class, are valued for medicinal properties. The Compositce are 
abundant in our own country, and the botanical student can never find difficulty in 
procuring specimens of this natural order. In commencing botanical studies with 
the flowers of spring, nature gradually presents us with those that are more and 
more difficult to investigate. The Compositte bloom mostly in the latter part dl 
the season. Being previously prepared by a knowledge of the general principles 
of classification, and observations of plants, this great natural order may be studied 
with satisfaction; whereas, if a course of botanical study were to be commenced 
with these plants, the student would find himself thrown amidst a chaos of facts 
with no clew to their arrangement. 
LECTUEE XXXY. 
GYNANDRIA, STAMENS ADHERING TO TIIE PISTIL. 
267. We shall now examine a class in which an entirely 
new circumstance from any yet considered, is regarded as form- 
ing its essential character : this is the situation of the stamens 
upon the pistil / the stamens adhering to that organ. In some 
cases the stamens proceed from the ovary, in others from the 
style. There is sometimes difficulty in deciding as to the num- 
ber of stamens, for they are not here, as in other classes, distinct 
organs, but in some cases mere collections of glutinous pollen, 
called polli7iia. The column formed by the union of the sta- 
mens to the pistil is called a gynostanium^ from gune^ pistil, and 
aner^ stamen. 
268. Order Monandria, one stamen. — The orders in this class, as in Monadelphia 
and Diadelphia, depend on the number of stamens or pollinia. The first ordei 
contains such plants as have but one stamen, or two masses of glutinous pollen, 
equal to one stamen ; this order is divided into sections, with reference to the man- 
ner in which the anther is attached to the style ; whether easily separated, whether 
the anther coheres to the top of the stigma, and also to the shape of the masses of 
pollen which are called the anther. 
269. The type of the natural order OrcliideaceeB is the orchis 
genus, consisting of many species of perennial plants which 
grow in shady, moist places ; some are parasites, adhering to the 
bark of trees by their fleshy, tuberous stems, and fibrous roots. 
The corolla shows a division into six parts as in lilies, but these 
are of different forms, and in several combinations; five of 
these parts are always external, but frequently in two ranges, 
as in orchis, where the three external resemble a calyx ; and 
there are then two internal divisions like petals, closing together 
beneath one of the external segments, so as to resemble a hood 
or helmet. The sixth segment or lip (for these flowers always 
«. Plants of this class valued for medicinal properties — Found in the latter part of the season. — 5J67 
Class G"P.andria. — 268. 1st order. — 269. Natural order Orchidaceae. 
