Apocynum androsaemi folium L. 

 DOGBANE FAMILY 



Although placed by botanists in a separate family, the dogbanes 

 are allied to the milkweeds. The same kind of milky juice 

 promptly oozes from the slightest abrasion of their delicate 

 skin. Both have simple leaves with entire margins, and both 

 bear pods filled with down-tufted seeds; but, whereas the pods 

 of the milkweeds are fat, spindle-shaped, and upright, those of 

 the dogbanes are long, slender, and drooping. In bloom also they 

 differ, the umbelled, complex flowers of the milkweeds being 

 replaced in the dogbanes by open clusters of simple bell-shaped 

 flowers. 



The Spreading Dogbane, a common plant throughout Canada, 

 grows on wooded banks, among thickets, in fields, and along 

 roadsides. Studied in these different situations, it exemplifies 

 very nicely the influence of illumination on plant form and growth. 

 In woodlands the plant is tall, and the leaves on each branch are 

 arranged in one plane in order to take full advantage of the 

 overhead light; the flower clusters terminating the branches are 

 comparatively small, and the whole effect is that of a richly- 

 leaved plant sparingly adorned with pretty pink blossoms. In 

 full sunlight the plant is lower and more spreading, the leaves are 

 smaller, relatively fewer in number, and more or less twisted 

 out of the horizontal plane. The flowers on the other hand are 

 much more abundant, and often the large open clusters on the 

 more numerous branches unite to form a floral hemisphere, or 

 sometimes almost a sphere within which the leaves seem of quite 

 secondary importance. 



As might be expected, the plants growing in the open bear 

 the greater number of seed pods, for insects love the sunshine, 

 and, like the milkweeds, the Spreading Dogbane is dependent 

 upon their good offices for the fertilization of its flowers. It 

 has, however, a terrible way of punishing certain small flies 

 who apparenty are unable to be of service in this matter and 

 yet desire the flower's nectar. As the unwelcome visitor eagerly 

 reaches for the honey, it frequently happens that his tongue is 

 caught in a notch in the centre of the flower, and, unable to free 

 himself, the unhappy creature slowly dies of starvation. In the 

 shade this tragedy is seldom seen, but in sunshine it is so common 

 that the plant is sometimes called Fly-trap. 



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