BOTANY. 
the dandelion ; tubular, forming a globose 
head, as in the thistle ; or tubular, and level 
at the top ; or discoid, as in lavender cot- 
ton, saiitolina. 
2. Polygamia Superflua. Florets of the 
disk like the discoid, flowers of the last or- 
der, and, like them, perfect within them- 
selves. Those of the margin furnished with 
pistils only, but all the florets produce per- 
fect seed. In this order the marginal flo- 
rets are sometimes minute and inconspi- 
cuous, but they are for the most part ligu- 
late, and from diverging rays, as in the 
daisy, aster, chrysanthemum, &c. 
3. Polygamia Frustranea. Differs from the 
last order only in having the florets of the 
margin abortive or neuter; in the former 
case there are no rudiments of a pistil in 
these florets, as in centaurea ; or there are 
abortive pistils, as in the sun-flower. This 
order is considered by Du. Smith as not es- 
sentially different from the last. 
4. Polygamia necessaria. Florets of the 
disk furnished with perfect stamens only, 
those of the margin w ith perfect pistils only, 
as in the garden marigold, calendula. 
5. Polygamia Segregate. Several flowers, 
either simple or compound, with united an- 
thers, and a partial calyx, all included in 
one general calyx, as the globe thistle, &c. 
Another order follows in Linnaeus, called 
Monogamia, consisting of simple flowers 
with united anthers ; but this order is now 
generally abolished. The circumstance of 
the union of the anthers in simple flowers 
being extremely various and uncertain, 
though in compound ones scarcely liable to 
any exception. 
XX. Gynandria. Stamens inserted either 
upon the style or germen. Such is the true 
idea of this class, and its character thus un- 
derstood is as much founded in nature and 
reality as that of any other ; by which we 
do not mean, that the class is a natural one, 
like the 19th, as it, in fact, comprises seve- 
ral natural families, whose allies may happen 
to be in other classes. Linnaeus, in his idea 
of this class, has understood as belonging to 
it, many plants whose stamens did not really 
grow out of the germen, as the passion- 
flower, the sisyrinchium, &c. Hence Thun- 
berg, and some other botanists, have judged 
the class altogether untenable. In the or- 
ders some alterations have recently been 
made by Dr. Smith, the reasons for which 
are more fully particularized in his Intro- 
duction to Botany, than we have room here 
to explain. These orders are distinguished 
by the number of stamens. Monandria, 
the first of them, contains almost all the Or- 
chis tribe. To the fifth, Pentandria, Dr. 
Smith refers many of the natural family of 
Contortae, as Pergularia, Cynanchum and 
Asclepias, a curious tribe, the structure of 
whose organs of impregnation is extremely 
puzzling even to the botanical adept. They 
have hitherto been placed in the fifth class, 
and some have thought they should be re- 
ferred to the tenth. In the 6th order of 
this class, -Hexandria, we find the aristolo- 
chia, or birth-wort. 
XXI. Monoecia. Stamens and pistils in 
separate flowers, but on the same plant. 
The orders of this class are, like those of 
the last, distinguished by the number of the 
stamens, or by some other character of the 
foregoing classes. The most genuine ex- 
amples of it are such as have a different 
structure in the two kinds of flowers, be- 
sides the essential difference with respect to 
stamens and pistils, as the oak, chesnut, 
lrazle. 
XXII. Dioecia. Stamens and pistils like 
the former in separate flowers, but on two 
separate plants. 
The orders of this class are characterised 
like those of the preceding. The willow, 
hop, hemp, &c. belong to it. 
XIII. Polygamia. Stamens and pistils 
separate in some flowers, united in others, 
either on one, two, or three distinct plants^ 
Dr. Smith has first suggested that no plants 
should be admitted into this class without a 
difference in the accessory parts of their 
flowers, over and above what concerns the 
stamens and the pistils. Without such a 
rule the class would be overwhelmed with 
the trees of tropical countries. 
The orders areMonoecia, when the several 
kinds of flowers grow on one plant, as Atri- 
plex ; Dioecia, when they are situated on 
two separate ones ; andTrioecia, when they 
occupy three several individuals of the same 
species. 
XXIV. Cryptogamia. Stamens and pis- 
tils either not well ascertained, or not to be 
numbered with certainty. 
1 . Filices, ferns, whose flowers are almost 
entirely unknown. The seed-vessels com- 
monly grow on the back of the leaf, thence 
denominated a frond, and are either naked 
or covered with a membrane. In some few 
they form spikes or clusters of capsules. 
2. Musci, mosses, a peculiar family of 
plants, possessing great elegance, though 
diminutive in size ; extremely tenacious of 
life, growing in the hottest as well as the 
coldest climates ; flourishing most in the 
