OF LEAVES. 
heaves considered with regard to the manner in which they succeed each other in dif¬ 
ferent stages of the 'plant. 
1. Seminal , leaves which come up with the plant when it first ap¬ 
pears above the surface of the earth; as in the garden bean ; these 
leaves are only the cotyledons, or lobes of the seed, which, after nour¬ 
ishing the young plant, decay. 
2. Primordial , leaves growing immediately after the seminal 
leaves, and resembling them in position, form, and size. The pri¬ 
mordial 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 which are found in the mature state of the 
plant; or according to the idea above advanced, 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 characteris¬ 
tic leaf, is the only one which appears. 
Form of Leaves. 
The form of the leaf is expressed by various terms borrowed from 
the names of different objects ; as palmate , hand-shaped ; digitate, 
from digitus, the finger, &c. We will illustrate some of the most 
common forms of simple leaves, leaving you to consult the vocabu¬ 
lary for many terms, which it would be too tedious to attempt to de¬ 
fine in the body of this work. 
Orbicular , or the round leaf; the Nasturtion affords an example of 
this kind, (See Fig. 38, a;) this is also peltate, having its petiole in¬ 
serted into the centre of the leaf, and thus resembling a shield. 
Reniform , (from the Latin ren , the kidney,) or as it is sometimes 
called kidney-form; the Ground-ivy ( Glechoma) has a leaf of this 
kind, (See Fig. 38, b ;) it is crenate , or has a margin with scalloped 
divisions ; ciliate , being fringed with hairs, like eyelashes. 
Cordate, (from the Latin cor, the heart,) or heart-shaped . Fig. 38, 
c, represents a cordate leaf with an acuminated point, that is, acute 
and turned to one side ; the margin is serrated, or notched like the 
teeth of a saw; this kind of leaf may be seen in the Aster cordifolium. 
or aster with a heart-shaped leaf. 
Fig. 39. 
Ovate, obovate, 
oval; these are 
terms derived from 
the Latin ovum, an 
egg; suppose the 
figure at 39, a, to 
represent an egg ; you observe that one end is broader than the 
other; now, if to this broad end you add a petiole, prolonging it into 
Leaves with respect to succ$ssion- 
ate—Ovate—Obovate—Oval. 
-Form of Leaves—Orbicular—Reniform—Cord- 
