80 APPENDAGES TO PLANTS. 
Clematis virginica, or virgin’s bower, which has beauti- 
ful pure white flowers. 
8th. Pubescence includes all the down, hairs, woolliness, or silk- 
iness of plants. The pubescence of plants varies in differ- 
ent soils, and with different modes of cultivation. But the 
species in some genera of plants are distinguished by the 
direction of the hairs. The microscope is sometimes nec- 
essary in determining with precision the existence and di- 
rection of the pubescence. It has been suggested that the 
uses of these appendages may be for similar purposes as 
the furs, hairs, and bristles of animals ; to defend the plants 
from cold, and injuries from other causes. 
Fig. 16. 
9th. The Bract is a leaf among or near 
the flowers, different from the leaves 
of the plant. Y ou may in this branch 
Fig. 16. observe the difference be- 
tween the real leaves (b.b.) and the 
bract (a); the former being cordate 
and crenate, the latter lanceolate and 
entire. 
In some plants as in several species 
of sage, the transition from leaves to 
bracts, is so gradual, as to render it 
difficult to distinguish between them, 
and a considerable part of the foliage, 
is composed of the bracts. In some 
plants, as the crown imperial, the 
stem is terminated by a number of 
large and conspicuous bracts. These 
appendages are sometimes mistaken 
for the calyx. Bracts are either green 
or coloured , deciduous or persistent. 
The Orchis tribe have green leaf-bracts. 
No plants of the class Tetradynamia 
have bracts. 
We have now in regular order, considered the first of the two 
classes of vegetable organs, viz : such as tend to the support 
and growth of the plant including root, stem, leaf and append- 
ages. 
Pubescence — Bract — Difference between the real leaf and the bract — Re- 
capitulation. 
