THE DEVELOPMENT OF THE CHASMOGAMOUS 



AND THE CLEISTOGAMOUS FLOWERS 



OF IMPATIENS FULVA 



BY 



Franklin B. Carroll, M. A., Ph. D. 

 With Plates LV, LVI, LVII. 



(Thesis presented to the Faculty of the Graduate School 

 in partial fulfilment of the requirements for 

 the Degree of Doctor of Philosophy). 



I. General Description of Growth, Habits, Size of Plants, 



Habitat and Coloring 



The Balsaminaceae include two genera, Hydrocera and Impatiens. 

 Hydrocera is a monotypic genus of Asia. Impatiens includes 400 species 

 mostly distributed through tropical Africa and Asia. A few species 

 occur in the North Temperate Zone. Nine species of Impatiens occur 

 in North America. Impatiens fulva is stated to occur in moist ground, 

 from Nova Scotia to Oregon and Alaska, south to Florida and Missouri. 



Impatiens fulva is usually described as a succulent herb, two to 

 five feet in height. These figures represent an average height, but they 

 do not include the whole range of variations generally met under dif- 

 ferent conditions. Under conditions which may be somewhat adverse, 

 but not sufficiently adverse to cause any diminution in the produc- 

 tivity of the plants, lower plants are frequently to be found. In one 

 locality that has been under observation for two years, the plants have 

 never attained a growth of more than eight inches. The locality is a 

 somewhat marshy piece of ground about twenty-five square yards in 

 extent, at the foot of a hill, in close proximity to a spring and brook, 

 and in rather heavy woodland shade. Even in dry weather the piece 

 of ground remains rather marshy. In the two years that these plants 

 have been under observation, they have produced only cleistogamous 

 flowers, but these in abundance. Although rather pale green, these 

 plants seemed perfectly healthy. The failure to attain greater height 

 apparently is related to the bog conditions, perhaps the toxicity of 

 bog water. To determine whether the height of these plants could be 

 explained ecologically, several seedlings were transplanted in June 1916 

 to four-inch pots of drier soil. The average height of these transplanted 



