46 
FLORA AND SYLVA 
is due to the thick outer husk, which 
makes good and bad so nearly equal in 
weight as to hinder separation by me- 
chanical means. Another reason is the 
smallness of the cones. When fresh, 
from 60,000 to 100,000 seeds go the 
pound, according to quality. It ger- 
minates in three or four weeks and will 
keep good for as many years, two to 
three years being needed to raise useful 
plants. Where Larch is sown in quan- 
tity it is usual to steep the seed in water 
for a fortnight or so before sowing in 
the s 
prmg 
; this softens the hard outer 
husk, and hastens germination. 
Larch Disease. — The Larch, like all 
the trees of Europe, has a great many 
diseases, but the one that affects us most 
is that known as "Canker," and the work 
of a fungus [Dasycypha calycind) which 
has the power not only of living on the 
outside but also of making its way into 
the heart of the tree. The first sign of 
this disease is an unhealthy look about 
the needles, and their early fall. Spots 
soon follow upon the twigs and bran- 
ches, and the pretty cup-like spores of 
the fungus (called Peziza) appear upon 
resinous wounds or swellings, spreading 
the disorder as they ripen. The remedy 
is difficult,not to say impossible,to apply 
in any thorough way. Not unlikely our 
mild open winters, which are so different 
from the arctic winters in which the 
Larch usually lives, have something to 
do with it, and also, owing to the great 
popularity of the tree, the fashion in 
which it has been planted in masses, very 
often absurdly close. We have seen it 
planted 18 inches apart, and so weak 
that the wind blew the trees over. If 
the disease occurs in such conditions it 
spreads rapidly. The remedy is to group 
the Larch more in open and airy places, 
and the higher and more exposed the 
better. If used in our moist valleys it 
is better to go in for mixed planting 
instead of massing, although here and 
there one must mass. 
References. — Evelyn, Silva, p. 309 ; Loudon, Abor- 
etum, vol. 4, p. 2350 ; Selby, British Forest Trees, p. 483 ; 
Veitch's Manual, p. 125 ; Cobbett, Woodlands, par. 311 ; 
Gordon, Pinetum, p. 168 ; Webster, Hardy Coniferous 
Trees, p. 65 ; Mouillefert, Essences Forestieres, p. 350 ; 
Cannon, Semer et Planter, pp. 56 and 159 ; Mathieu, 
Flore Forestiere, p. 555 ; Boppe and Jolyet, Les Forets, 
p. 90 : Forbes, English Estate Forestry, p. 87 ; Michie, 
The Larch, culture and management ; and many notes in 
Woods and Forests. 
H. CORREVON. 
JACOBINIA (JUSTICIA). 
These soft-wooded hothouse plants 
have suffered much through changes, for 
all have been known under other names, 
and several have quite an appalling list of 
synonyms. The group has been partly 
torn from Justicia, a large tropical genus 
now little grown in gardens, and widely 
scattered over the warmer parts of the 
world in India, Africa, and South Amer- 
ica. A few other plants long known as 
Libonia,Sericographis,and Sericobonia, 
are also included with them. As now 
understood Jacobinia includes some 30 
to 40 species of hothouse plants from 
Mexico and the warmer parts of South 
America, with tubular flowers of scarlet, 
orange, yellow, or pink. While in most 
cases crowded together in dense heads, 
in some the flowers are arranged as sparse 
clusters which are more useful for cut- 
ting. Though forming shrubs or even 
low trees of 10 or more feet in their own 
country, their gaunt straight stems are 
against the use of old plants in the green- 
house and it is usual to discard them 
