Missouri Botanical 
Garden Bulletin 
Vol. III St. Louis, Mo., May, 1915 No. 5 
INSECTIVOROUS PLANTS 
The destruction of vegetable life by the voracious attacks 
of insects is well known, but that there are certain plants 
which obtain important elements of their food from insects 
which they have caught in one way or another is not so 
widely appreciated. Representatives of this group of remark- 
ably specialized plants are now to be seen on exhibit in the 
north vestibule of the Nepenthes House. 
A number of plants show contrivances which obviousl 
have for their function the capture and retention of suc 
small creatures as may fly or creep upon their leaves; and 
it has been ascertained by experiments that the majority of 
these plants use the animals they capture, in one way or 
another, as sources of food. For the most part the plants in 
question prey upon insects, and hence the term “‘insectivorous 
plants” has been rather generally applied to them; it has 
been estimated that there are now known about five hundred 
such plants. 
_ By a consideration of the special adaptations for capturing 
insects, these plants nidyralty, group themselves into three 
distinct sections, two of which are represented in the collec- 
tion at the Garden. The first section contains those forms 
in which chambers are developed into which small animals 
may enter, but from which it is impossible for them to escape. 
These plants exhibit no movement of any kind. To this 
group belong the genera Nepenthes! and Sarracenia, of which 
a number of species are on exhibit. The second section em- 
braces those forms which show a definite movement ay a 
to cover the prey with as great a quantity of digestive fluid 
as possible, a movement which may in some cases, as in 
Dionaea, also serve to capture the insects. To this section 
belong the genera Pinguicula, Drosera, and Dionaea. Many 
representatives of these, too, are in the collection. The third 
* An account of these interesting plants and the collection at the 
Garden may be found in the October, 1913, number of the BULLETIN. 
(61) 
