LEAVES. 
69 
roof of a house ; in the monk’s hood they are bent downwards 
towards the petiole. 
Some plants are destitute of leaves ; they are then called 
Aphyllous , which term signifies wanting leaves. 
In determining the species of plants, the leaves are much re- 
garded ; specific names are often given from some circumstance 
of the leaf, for example ; the IIepatica triloba is that species of 
the Hepatica, which has leaves with three divisions called lobes; 
the viola rotundifolia is a species of violet with round leaves. 
A knowledge of the various appearances presented by leaves, 
is of great importance ; in order to become acquainted with all 
their varieties, considerable practice in the analysis of plants is 
necessary. Plates will assist you in understanding the defini- 
tions, but you must chiefly consult nature. There are many 
terms to express the varieties observable in leaves ; we shall 
here explain some of the most important. 
1st. Leaves considered with regard to the manner in which 
they succeed each other in di[j'erent stages of the plant. 
1. Seminal , leaves which come up with the plant when it 
first appears above the surface of the earth : as in the gar- 
den bean ; these leaves are only the cotyledons or sides 
of the seed, which, after nourishing the young plant, 
decay. 
2. Primordial , leaves growing immediately after the semin- 
al leaves, and resembling them in position, form, midsize. 
The primordial leaf, according to the fanciful idea of a 
French botanist, is a sketch which nature makes before the 
perfection of her work. 
3. Characteristic, leaves are those which are found in the ma- 
ture state of the plant ; or according to the idea above ad- 
vanced, nature in them perfects her design. 
It is not always, however, that this process with regard to 
change of leaves takes place ; as in many cases the proper, or 
characteristic leaf, is the only one which appears. 
Leaves, with respect to insertion , arc, 
Radical , (from Radix, the root,) springing' from the root, as the Dande- 
lion. 
Cauline, (from Caulis, the stem,) growing out of the stem. 
Floral , growinsr near to the flower, sometimes called bracts. 
Peltate , when the foot stalk, or petiole, is inserted into the middle of a 
leaf, like the arm of a man holding a shield. 
Amplexicaut , leaves clasping the stem with their base. 
Connate , united at their base. 
Perfoliate, when the stem passes through the leaf. 
Imbricate, lying one over another, like the shingles of a house. 
Aphyllous — Leaves furnish specific characters — Leaves with respect to 
succession — Insertion. 
