APOCYNACEAE 



DOGBANE FAMILY 



CLIMBING DOGBANE 



Trachclospcrmum difforme (Walt.) Gray 



The Climbing Dogbane is found in Illinois only in the 

 southernmost counties. It grows in moist woods and along 

 streams from Delaware southward, mostly near the coast, to 

 Florida, and from Illinois and Mis- 

 souri to Texas and Mexico. Only this 

 species occurs in 

 North America but 

 a few others are 

 natives of eastern 

 Asia. 



This plant is a 

 more or less woody, 

 twining and high- 

 climbing vine, with 

 milky juice, thin 

 opposite leaves and 

 yellow or creamy 

 flowers. Usually the 

 whole plant is 

 smooth but some- 

 times the young 

 twigs are somewhat 

 hairy. The stems are 

 one-half inch or 

 more in diameter. 



The flowers are produced from June to August. The small 

 green calyx is glandular inside and has 5 narrow acuminate 

 lobes. The yellowish corolla is funnel shaped and 5-lobed at the 

 end, the lobes being rolled back and more or less twisted. The 

 5 stamens are attached to the base of the corolla tube. The 

 filaments are separate but the arrow-shaped anthers are close 

 together around the stigma, to which they cling slightly. The 

 1 ovaries and 1 slender styles are distinct but the stigmas are 

 united. The ovaries develop into long slender follicles which 

 when mature are 5-9 inches long. Each follicle contains numer- 

 ous small oblong seeds that have a tuft of long hairs at i end. 

 Because of these hairs the seeds are readily scattered by the 

 wind. 



!39 



