RUDIMENTS OF THE NATURAL SYSTEM OF BOTANY. 
161 
to the extent of one-sixth only, a set of plants may be irretrievably injured. But 
heath-soil, (falsely called peat,) though its components may vary a little, yet 
contains only pure sand and black vegetable matter, and can rarely injure an 
Azalea. 
We must not conceal the fact that none but the most adroit and experienced, 
aided by the best machinery, can hope to attain a set of plants in four or five weeks. 
Yet, if an amateur do not work speedily, he may attain his object slowly and surely, 
by placing cuttings in sand, over drained heath-soil, even in a cold frame ; the pot be- 
ing covered with a bell-glass. Months, nay the winter, may be passed over without 
obtaining growth, yet roots will be protruded early in the spring, after placing the 
pots in temperate heat, as of a stove or gentle hotbed. We have just potted off 
eight or nine young plants which were so treated, and witnessed a similar result at 
a nursery in Berks, with a pot of cuttings taken in August 1839. 
RUDIMENTS OF THE NATURAL SYSTEM OF BOTANY. 
NO, IV. 
Words being the principal means through which information can be imparted, 
it becomes of the greatest import that those employed in scientific dissertation or 
description should not be liable to misconstruction, or convey aught but a simple 
and universally recognised meaning. To obviate any mistake with reference to the 
peculiar phrases we from time to time make use of, and to furnish definite notions 
concerning the exact nature of the more tangible vegetable organs, we have before 
explained some of the terms most common to gardening literature, and shall, with- 
out further introduction, go forward with this task. 
"Forms of inflorescence" says Dr. Lindley, "are occasionally, but not often, 
found characteristic of peculiar tribes." They are greatly varied in different orders, 
and even in genera and species of the same genus likewise, but there are kinds 
which essentially mark certain groups. The chief of them may here be noted. 
Composite flowers are those which have an indefinite number of small blossoms — 
which, from their abundance and densely segregated disposition, altogether 
nominally composing but one flower, and hence considered only parts of it, 
are called florets — collected into a head on the summits of the peduncles or flower- 
stalks. Each of these little florets will, if examined, be seen to display all the main 
features of larger flowers. Where the inflorescence thus constitutes a close cluster, 
it is termed capitulate. 
Some sorts of plants that bear male and female flowers distinct from each other 
have the former arranged round a central stalk or axis. These have no calyx, and 
fall off in one piece when they have fulfilled their destined ofllces, or remained open 
for the ordinary period. This species of inflorescence is denominated a catkin or 
amentum. It is very observable in the nut, birch, alder, &c. 
VOL. VII.— NO. LXXIX. Y 
