350 
THE GARDENERS' CHRONICLE OF AMERICA. 
Cardinal Flower (Lobelia cardinalis). 
FLOWERS PUMPING AND EXPLODING. 
T^ACH August for many a year I have watched for the 
coming of the cardinal flower (Lobelia cardinalis) 
and, knowing the family to which it belongs, and where 
it dwells by the river's brink, I believed that I knew the 
flower itself, until one dav last summer when I decided 
to examine its mechanism, writes Herbert W. Faulkner 
in "Guide to Nature." I was surprised at the "mystery" 
that it revealed, and that I can best describe by compar- 
ing the structure to a pump, whose cylinder is formed by 
the anthers united into a tube and whose piston is the 
stigma pushed forward by the growing style as the piston 
rod. The pollen is shed in the cylinder, is compressed 
there and is eager to escape. 
^ "hen an insect drinks from the flower and backs out, 
he scrapes against a valve at the outer end of the tube, 
opens it and receives a charge of pollen on his back. We, 
too, can open the valve and see the pollen ooze out, and 
when we have set it all free, we see the stigma with its 
odd terminal rosette emerge and make ready for the 
touch of the pollen that must come from another flower. 
Other lobelias which I have examined prove to possess 
a similar apparatus to insure their cross-fertilization. 
Many of the pulse family push their pollen at their 
insect guests, but none are more active in this way than 
the tick trefoil (Desmodiuin nudiflorum). The small, 
pink flowers grow in a loose spike and resemble a sweet 
pea blossom in form with hood, wings and keel. The 
pistil, stamens and pollen are all securely enclosed in the 
keel until an insect alights on it, when out they jump 
with a veritable explosion, the pollen flying in a cloud 
and dusting the astonished guest. The Desmodium, how- 
ever, it not a magazine gun. One shot bursts it open 
and thereafter its pistil is exposed to receive the pollen 
from another plant. The sketches show a flower before 
and after the explosion. 
The fringed orchids (Habenaria) treat their insect 
visitors as beasts of burden, clapping a package of pollen 
on their backs and gluing it there "for keeps." These 
pollen packages tied up in the form of clubs with adhe- 
sive handles lie exposed and waiting in little grooves or 
pockets close to the opening of the money wells where 
they will surely fasten themselves to the head or the eye 
of a thirsty insect. 
In the first sketch, representing a section of a flower 
of the purple fringed orchis, is seen a pollen club being 
Courtesy of The Guide to Nature. 
Purple Fringed Orchis (Habenaria). 
