flo\\i:rs pumping and exploding 



11 



Flowers Pumping and Exploding. 



I'.\' lii:RI!l'.KT W. FAlLKXlvU. WAS 1 1 I X CTC )X , 

 CONNl'X'TICfP. 



Each August for many a year 1 have 

 watched for the comiiii^' of the cardinal 

 flower (Lobelia cardinalis } and, knowing 

 the family to wdiich it belongs, and where 

 it dwells by the river's brink, I believed 

 that I knew the flower itself, until one day 

 last summer wheni I decided to examine 

 its mechanism. I was surprised at the 

 "mystery" that it revealed, and that I can 

 best describe by comparing 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 compress- 

 ed there and is eager to escape. 



When ani 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. 



^Nlanv of the pulse family nush their 

 pollen at their insect guests, but none are 

 more active in this way than the tick tre- 

 foil fDcsuwdiitin midiflorum). The small, 

 oink flowers grow in a loose spike and re- 

 '^emble 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 aligihts on it, when out 

 thev juniD wdth a veritable exnlosion, the 

 Dollen flving in a cloud and dusting the 

 astonished suest. The Desmodium. hoAv- 



CARDINAL FLOWER. 



ever, is not a magazine gun. One shot 

 bursts it open and thereafter its pistil is 

 exposed to receive the pollen from an- 

 other 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 packag^e of pollen on their 



TICK TREFOIL 



