AN ENCYCLOPAEDIA 
OF HORTICULTURE. 249 
Puccinia—continued. 
gcidiospores. Like the latter, they germinate almost 
at once, and push their mycelium into the tissues of the 
host-plant through the stomata. 
8. The Teleutospore (from teleutaia, final, and spora; 
so called because it is the final form in the cycle) is 
sometimes called the Pucciniospore ; but this name is less 
suitable, as other genera besides Puccinia produce such 
spores. These are, in most cases, produced on the same 
substratum as the uredospores, but later in the season; 
Fig. 320. GROUP OF SPORES OF PUCCINIA GRAMINIS—a@, Uredo- 
spores, formed in ory summer ; t, Teleutospore, formed later 
in the season; st, Stalks supporting the Spores. 
and they are most often developed only in late summer, 
‘They grow on erect footstalks or branches, to which they 
3 ally remain long united, and they are considerably 
E er-walled and darker than the others, from which 
also they differ in form (see Fig. 320). They may be 
; _ one-celled (Uromyces), two-celled (Puccinia and Gymno- 
= sporangium), or three- or more-celled (Triphragmium 
and Phragmidium). The teleutospores, for the most 
part, remain for a considerable time without germinating, 
often continuing unchanged all winter. On germinating 
Fig. 321. PUCCINIA GRAMINIS—Teleutospore germinating and 
ducing Sporidia (sp) on tips of small stalks (st); pr, Mycelium 
Tube growing out of the Spore. 
™ (eee Fig. $21), a mycelium tube is pushed out from each 
cell, or only from one. 
divided near the tip, by cross walls, into a row of cells, 
from each of -which a small branch arises, and bears, at 
its tip, a small, rounded or oval body, called a sporidium. 
The sporidia produce a new mycelium, which penetrates 
into suitable host-plants, and frequently gives rise to 
æcidia in them. Occasionally, two forms of teleuto- 
Spores occur in the same Fungus, e.g., one-celled and 
two-celled in Puccinia miata. In most of the species, the 
cycle is not so complete as the above; and, in fact, it 
has been traced, as yet, in but few species. As has 
already been said, most cryptogamic botanists believe 
that some of the species live, during part of the cycle, on 
one food-plant, and during the other part on another. 
Such species are said to be heterwcious (from heteros, 
different, and oikos, a home). Those that live on a single 
food-plant during the whole cycle are said to be aut- 
cecious (from autos, the same, and oikos). 
Puccinia is readily distinguished, in the perfect con- 
dition, from other genera of Uredinee by the telento- 
spores being free from one another and two-celled; or, at 
least, there are two-celled spores, associated, in a few 
Species, with three- or more-celled abnormal exceptions, 
or with a one-celled form, much like the teleutospores 
of the allied genus Uromyces. The- two-celled spores 
vary in length of stalks, in forms, and in surface- 
markings of the cells, &c.; and on these characters we 
must depend for distinguishing the species. The genus, 
in the systems in most frequent use on the Continent, 
is broken up into sections differing from one another in 
the completeness of the cycle, so far as known, and in 
other minor peculiarities. oe oc igi 
Vol. IIL 5 
+ * 
-+ , 
These tubes often become- 
Puccinia—continued. A 
Owing to the parasitic habit of the very numerous 
species included in the genus, there are few genera of 
Fungi more directly injurious ; and a considerable number __ 
grow on and damage garden and field produce. The 
injurious effects are due, in some cases, to the abstrac- 
tion of nourishment by the mycelium of the Fungus from 
the food-cells ofthe plant, and to the injury done to 
the epidermis by the spore-masses tearing it off the 
tissues. beneath. These tissues, in consequence, cease 
to do their part in supplying food to the plant. In a 
smaller number of cases, the plant is stimulated by the 
Fungus to a local over-production of diseased cellular 
tissue. This is peculiarly the case inthe wcidium stage, 
e.g., on Barberry, on Gooseberry, and on Mints. In some _ 
cases, plants may suffer extremely, and may even be 
killed by the Fungi (e.g, P. Malvacearum almost ex- 
tirpated Hollyhocks in many districts a few years ago), 
or, if not killed, may be much distorted by them; e.g., 
Mints attacked by the ecidium of P. Menthw, Anemones 
bearing P. Anemones, &c. In many cases, the plants 
are simply weakened, without marked distortion; egs 
cereals affected badly by the red and black rusts 
(P. graminis and P. straminis), and Onions overgrown 
by P. mixta. Some do not seem to injure —— 
the plants affected by them, but this is eptiona 
Their growth and distribution are favoured by 1 
which promotes the formation 
spores, get a ihe a 
Remedies. As usual with internal parasites, no eure 
is known for plants, or parts of plants, attacked by the: 
Fungi; hence, remedies must be directed to the preven- 
tion of the spread of disease. This is best accomplished — 
by the removal and destruction of the infested struc- 
tures, where this is possible. Where the attack is very 
serious, e.g., in the case of Hollyhocks and of Onions, 
it is good policy to sacrifice the entire crop, if neces- 
sary, to preserve that of the following year from infec- 
tion. As already said, moisture favours the distribution 
of the Fungi, and the soil should, therefore, be well 
drained. Lastly, where the burtful Fungi are believed 
to be hetercecious, it is well to remove the supposed 
intermediate host-plant; e.g., in the case of Puccinia 
graminis of cereals and other grasses, which is believed 
to live on Barberry-bushes as Æcidium Berberidis, the 
Barberries should be removed from the neighbourhood 
of the fields. Yet too much reliance must not be placed 
on this method, as these Fungi are known to thrive when 
restricted to the one food-plant. — 
In the following enumeration of the species of Puccinia 
falling under the observation of gardeners, those of 
which only telentospores are known are first mentioned, __ 
and afterwards those of a more complex nature. 
1. P. Bumi of orms dark, warty spots, in large — 
numbers, on leave: Box. Teleutospores alone are 
known. They are brown, smooth, and oblong or club- 
shaped. The Box does not, as a rule, seriously suffer. 
2, P. Malvaceartm is only too well known to most 
gardeners, because of its ravages on Hollyhocks, Mal- 
lows, and allied plants. For an account of the appear- 
ances produced, of the history of the Fungus, and of 
the injury done by it, see Hollyhock Fungus. Only 
teleutospores are known. ‘They are pale brown, smooth, 
and pointed at both ends. The plants suffering from 
the wth of this Fungus seldom recover, and often die 
in a short time. 
3. P. Arenarie belongs to the same group, having, 
so far as is known, only teleutospores; these are pal 
yellowish-brown, and slender. They form small, brown _ 
masses, often in irregularly - concentric groups, on the _ 
leaves of Pinks, and of many wild, as well as garden, 
Caryophyllaceous plants; but, unless the Fungus is 
very abundant, the host-plant is seldom endangered by 
, 2K 
