ON THE DISTINCTION OF VARIETIES OF PLANTS. 
105 
9. Pubescence is an uncertain mark, as by culture or change of soil 
plants are subject to lose their spines, as their hair or clown. 
10. Leaves , though for the most part they furnish most elegant 
specific differences, are yet subject to luxuriation in the same species, 
which must he carefully distinguished ; this may respect their oppo¬ 
sition and composition, and also their being crisp, or bullate. 
a. In respect to opposition, opposite leaves will sometimes become 
tern quatern, or quine, growing by threes, fours, or fives, and then the 
stem also from quadrangular (square) will become polygynous (of 
many sides.) 
b. In respect to composition, digitate leaves will frequently gain 
an addition of one or more folioles. 
c. Crisp or curled leaves are a frequent variety, there is a singu¬ 
larity observable in scented plants, that when the leaves are curled, 
the scent is heightened by the crispature. 
d. Bullate or bladdery leaves are generally produced from those 
that are rugose (wrinkled,) and this is owing to the increase of the sub¬ 
stance of the leaf within its vessels, which occasions it to swell and rise. 
Plants are sometimes found to vary from broad leaved (latifolia) to 
narrow leaved (angustifolia) but this variation is less frequent. 
11. Monstrous flowers, such as are multiplicate, full, or pro¬ 
liferous, derive their origin from natural ones, and therefore are only 
to be considered as a variety. 
Upon the whole, the change of soil is found to have a great effect 
on the nature of plants, and to this many of the varieties above men¬ 
tioned must be imputed. In like manner, the improvements which 
are made in the plants cultivated for fruit, as in Vitis, Pyrus, &c. 
and in all kinds of grain and pulse, are not to be esteemed as lasting, 
for all these, if left to themselves in a poor soil, would run off again, 
and resume the qualities they had when they grew wild. The soii 
also has some effect upon the leaves, for though it is less common for 
them to differ on the same plant, yet it is observed that watery soils 
are apt to produce a division in the lower leaves of the plant, and 
even to render capillary such as are produced under the water; and 
on the contrary, that montaneous plants usually have their upper 
leaves more divided, their lower ones more entire. Varieties may 
generally be explained and reduced under their proper species with 
ease, by conferring the variable marks of the variety with the natural 
plant. The whole order of the fungi, to the scandal of the science, is still 
a chaos, botanists not being able to decide with certainty what is a spe¬ 
cies or which is a variety. On the different forms of roots and leaves, 
in my next. 
K 
