74 



not infrequent in low grounds in central Iowa. The irregu- 

 lar flowers are deep red; the tube is straight and split down 

 on the upper side. The lower lip is spreading, three cleft. 

 Trelease observed that the humming bird, TrochihiS coluh- 

 ris, visits this species and Robertson says he has never failed 

 to find them about the flowers. He says: "The pendant 

 lip shows that the flower is intended to be visited by a bird 

 or insect which is in the habit of sucking the sweets from 

 flowers without resting upon them. I have also seen the 

 flower visited by Papilio philenor L. and P. trocilus L. " 



In Campanula rotundifolia the nectar 

 18 secreted by a yellow disk which sur 

 rounds the base of the style. It is covered by the bases of 

 five stamens. The interspaces are occupied by hairs, thus 

 protecting the honey from unbidden guests. In the 

 bud the three stigmas come together and form a cylinder, 

 the outer surface of which is covered with hairs. Before the 

 flower has opened the anthers are placed around the style. 



The stamens dehisce and pollen falls on the hairs of the 

 style. When the stamens have dehisced they 

 shrivel up, the style lengthens out and the flower opens, it is 

 then thickly covered with pollen. When an insect visits 

 the flower takes oflf some of the pollen, the hairs on the 

 brush shrivel and now the three divisions of the style ex- 

 pand and curve backward. An insect coming from a 

 younger flower will leave pollen on the stigma. The flowers 

 are therefore proterandrous. 



In the related Specularia perfoliata the early flowers are 

 cleistogamous. 



Lricaceae- Laurel {Kalmia latifoUa) a near relative 



