128 DISSEMINATION OF SEEDS. 



In the Tecoma radicans, trumpet-creeper, a beautiful 

 climber extensively cultivated in New England, an entire 

 wing surrounds the body of the seed. In the catalpa, 

 a plant closely allied to the last mentioned, the testa is 

 extended at each end into a membranous wing, fringed 

 and comose at the ends. As the pods containing the 

 seeds open, great numbers of seeds are liberated and 

 quickly scattered by the wind. 



The seeds of Asdepias, milkweed, are thin, flat, and of 

 a brownish color. They are produced in great numbers 

 and are arranged upon a large placenta which separates 

 at maturity from the suture. At one end of each seed 

 are many soft, satiny hairs called the coma. When the 

 seeds are ripe they become separated from the placenta 

 and the lightest breath of wind wafts them away from the 

 follicle and to their destined resting-place. The evident 

 design of the coma is to assist in the wide-spread distri- 

 bution of the species. Many of the seeds probably fall 

 near the plant which produced them, while chance breezes 

 carry others to a great distance. 



The seeds of JEJpilobium, or willow herb, are endowed 

 with a similar tuft of silky hairs to assist them in their 

 wanderings. This plant is often one of the first to grow 

 on land which has been burned and, for this reason, it 

 has been called in Maine and Nova Scotia fireweed. The 

 coma of the seeds causes them to be wafted by the winds 

 and, finding the ashes and burnt soil specially adapted to 

 their germination and growth, they speedily take posses- 

 sion and flourish. 



The seeds of plants belonging to the order /Salicaceoe, 

 the willows and the poplars, are furnished with a very 

 abundant silky or cottony down. The abundance of this 

 down on the fruit of one variety of poplar, Populus 

 balsamifera, makes the tree a disagreeable neighbor 

 during the period of fruiting. 



