- Scientific. 
pe RN Crt 
FERTILIZATION OF FLOWERS. 
I By siéma.] 
Ii. 
The Condollea (stylidium) is a native 
plant common around Adelaide. The 
mechanical arangement ‘provided for 
supplying the’ bees which © frequent ~ 
it with pollen is remarkable. In 
the centre of the flower is a_ long 
column,: which is really the pistil and 
stamens combined. At the end is the 
stigma surrounded by anthers. The latter 
nipen first, and have dried up and fallen | 
away before the stigma matures. This 
elongated column is very sensitive, and acts 
as follows: A bee is guided to the honey 
in such a way that it must touch the sen- 
sitive base of the column. Immediately 
the column springs up, and if the bee -s 
large enough, receives the pollen from the 
anthers. ., It is almostpinned down to the 
tube of the flower, and has to wriggle side- 
ways to get out, thus helping to brush the 
pollen off the anthers. . The column. after , 
a while returns to its former position, and . 
subsequently is ready when the stigma 18... 
spring up again and collect the pollen from 
the back of a bee which has just come from 
a younger flower: The action may be imitat- 
ed by touching the column with a piece of 
wire. . The fifth petal has formed into a 
sori of lip, which is provided with horns. 
These latter guide the column on its way 
back, and steer it to‘its correct position. 
Grevillea has the stigma doubled up out 
of the way until the anthers have ripened. 
Mimulus has a ‘style divided into two 
plates. As the insect pushes past into the 
flower one of these plates is bent down and 
sweeps off the pollen. As the insect emer- _ 
ges, this plate, being elastic, springs back 
against its fellow, and any new pollen col- ~ 
lected from the anthers of the flower rubs 
against the lower. insensitive side of the 
plate. f 
Orcuips.—Orchids being peculiar im 
structural arrangement, are particularly 
worthy of study. Ona column facing the 
lip of the flower are the stigmas and the 
anthers. The latter are situated at the 
top of this column, and the stigmas are” 
below to the right’ and left. The column | 
is prolonged into a rostellum or beak. The :; 
pollen is in large’ masses, each of which is ~ 
upon a stalk. Although the pollen is in 
such a position that ib might fall on ihe 
stigmatic surfaces, the latter are protected 
from it. Also the pollem is not in small 
grains ready for dispersion, and each mass 
is firmly fastened * by ~its stalk to the 
column. If a small piece of stick be pushed 
in against these pollen masses they adhere 
and stand erect; if now they be watched. 
for a‘while they ‘will be seen’ toybend down- | 
wards and slightly outwards. The reason is 
“THE AUSTRALIAN GARDENER. 
obvious. . A bee carries them away,;.,if 
. they remained erect they would simply be 
placed back again into the.same place cn 
~ another flower. 
However, after they bead 
forward they-are exactly in. the right posi- 
_ tion to strike the stigmatic surfaces. On 
contact with these latter small portions are 
., torn away, and adhere, leaving the remain- 
. der for fértilising other flowers. Only one ~ 
- orchid has dry pollen, but.a sticky mate-.. 
. vial is.exuded to make‘it adhere. 
The Catasetum is an orchid’ with male 
and female flowers separate; consequently 
it must be insect fertilised. It is remark- 
able for having the pollen masses on the 
end of a very.sensitive curved stalk. When 
a-bee alights on the lip it moves the long 
antenna-shaped appendage which acts like 
a trigger, and causes a fine membrane to 
break away and release the pollen stalk, 
the latter being in a high state of tension. 
Darwin tried the experiment. of touchiag 
the trigger with a hair, and found-the pol- » 
len masses were projected 3 ft.’on to a 
piece of glass.placed in the line of fire. 
In order to prove to‘ you. that 
certain insects are indispensable- for - 
fertilising certain flowers I may cite 
the case of the English clover, which was- 
planted in New Zealand. No seeding took 
place until the bumble bee was imported 
from England for that purpose. Seed 
readily formed after the arrival of that~ 
useful insect. . 
“In general, different groups’ of insects” 3 
according’ to their sense of taste or color, 
ripe and the anthers have dried away, to vite length of tongue, their movement and 
dexterity have produced various odors, 
colors, and forms of flowers. Insects and 
flowers have both progressed. towards per- 
fection,” so says one writer. 24 
As an example, one tropical orchid has a 
spur 12 in. long, and can only be fertilised 
by an insect which has a proboscis of that 
length. Insects with shorter tongues would 
not. visit the: flower, as the honey would be 
inaccessible to them. clan 
 Seseeseesss= 
LEUCOJUM HERNANDEZI. ~~ 
en 
are of an intense green color. 
is seen to the best advantage in the wilder 
portion of the garden, and in this it re- 
sembles the blue-flowered Commelina. 
Both are apt to be eclipsed by more showy 
subjects in the ordinary border ;: but: see 
them in some spot given over to ferns, 
some copse under deciduous trees, and 
then we appreciate fully their delicate 
beauty and graceful growth. . Leucojum 
The plant: 
SEPTEMBER 7, 1903. 
Hernandezi is considerably taller. thancthe 
well-known L. vernum ; indeed, it is more. 
closely/allied to the Summer Snowflake, L. 
estivum. lt. should be noted that whén 
the Leucojums are lifted and dried they 
should be. amongst the first bulbs to be 
replanted in autumn, as it is not advisable 
tc keep them out of the ground long. 
ae 
BRODIEA UNIFLORA. 
This plant is sometimes known as Tri- 
téleia, or the Spring Starflower. It is cer- 
tainly o1e of the, most beautiful of our 
early flo vering bulbous plants, and deserves 
a place in every garden. I saw it growing 
lately ip an old-fashioned garden, where 
ic had been left ‘undisturbed, and had 
grown into large bold clumps. The pale 
flowers, faintly tinged with color, are large, 
and are charmingly displayed growing out 
of a carpet of blue Forget-me-Nots. The 
plants need a sunny position, but are not 
particular as to soil. There are many 
other varieties of Brodiea that are far too 
seldom seen. , 
| SSeS se oso 
THE CATERPILLAR PLANT. 
Doubtless the long-suffering amateur 
would not hesitate to apply this name to 
many of the subjects in his garden, whose 
proneness for the company of caterpillars 
would render- the application justifiable. 
The real Caterpillar Plant, however, is 
very rarely seen in cultivation, and pro- 
bably most people have never seen it. © It 
is a hardy annual from Africa” and 
Southern Europe, and belongs to the great 
Pea family (Leguminose). 
Unlike most members of the family, it 
is, however, rather. lacking in beauty, and 
were it not for the very curious seed pods 
it bears would probably be entirely 
ignored. . It is these which give to the 
plant its popular name; they are borne 
singly on stalks from the axils of the 
leaves, and so much resemble caterpillars 
_ in their shape and markings.as to make 
the bestowal of the name comprehensible. 
Seeds are sown in the open in spring, 
and the plants treated in the way usual 
with hardy annuals; but as they do not 
make a great floral display they may have 
any odd corner of the garden allotted to 
them. Scorpiurus is the Caterpillar 
Piants’s generic name, and vermiculata is 
the species most generally grown. It 
blooms in June or July. 
E.-J. C. 
Royal Agricultural and “Hlonticultural society. 
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