370 Agricultural Weeds. 
Table II. — Ash Analyses of Weeds. 
1. Blyth. 
2. BIyth. 
3. Blyth. 
4. Liebig. 
5. Liebig. 
Veronica 
hederifolia.* 
Veronica 
hederifolia.* 
Leontodon 
taraxacum.f 
Af^rostemma 
githago.J 
Chelidonium 
majus. $ 
Stems and 
leaves. 
Seed? with 
capsules. 
Seeds without 
the pappus. 
mole 
plant. 
AVhoIe 
plant. 
Silica and Sand 
3 -.5 
27--1 
G-3 
32-3 
2'2 
2-7 
25-4 
4-2 
]3'2 
4-9 
21-4 
2-9 
14-3 
11'8 
2'4 
22-9 
29-3 
6-1 
1-4 
33-1 
23-4 
5-1 
Oxide of Iron . . . . | 
pel-- \^.o 
per- "1 J. 2 
oxide/ ^ 
per- 10.7 
oxide J ~ 
1-2 
1-2 
Chloride of Potassium 
, , of Sodium 
Phosphoric Acid 
Sulphuric Acid 
7-2 
14'1 
4-0 
I'O 
44-0 
3-4 
41-9 
4-3 
7-6 
7-2 
2-4 
3-4 
l.T-7 
2-3 
The Duration of Weeds. — On referring to our Table of 
Weeds, it will be seen that they have been arranged according to 
their duration of growth, as follows : — 
1. Annuals, — Plants which are perfected in the course of a 
single year, when, bringing forth their seeds, they die. 
2. Biennials. — Plants which occupy two seasons for perfecting- 
their seeds, bringing forth stem and leaves the first year, and 
flowering and seeding the second, and then die. 
3. Perennials. — Plants which, after they have perfected their 
seeds, continue life by means of buds — which are forming during 
the growth of seeds — for an indefinite period. 
It would at first sight appear that weeds of the first kind, 
though numerous, are not very formidable enemies ; but there 
are circumstances which render them exceedingly troublesome. 
They produce a great quantity of seed, and that oftentimes so 
quickly as to cause them too frequently to be neglected or over- 
looked at the most critical time. Now the seeds of an individual 
species are often enough for a crop ; but there are many species, 
which, all conspiring to the same end, make annual weeds for- 
midable ; and tlie reason why land is not overspread by weeds to 
a greater extent than is really the case is, that of the numerous 
seeds ploughed in in tillage many are buried too deep to ger- 
minate. We must not therefore suppose that because we kill 
* Veronica hederifolia. Ivy-leaved Speedwell, a common agrarian. 
+ Leontodon taraxacum, Dandelion, grows everywhere. 
X Aqroslemma (jilhayo. Corn Cockle, an agrarian. 
§ Chelidonium majus, Greater Celandine, usually about habitations. 
