FLOWERS OF IMPA TIENS FULVA 155 



were similar in all — a small, stagnant, poorly-drained spot in rather 

 dense shade. The plants in each were less than a foot in height, of a 

 pale green color, and producing rather sparingly cleistogamous, and 

 no chasmogamous flowers. The adverse condition here would seem tO' 

 be the toxicity of the bog water. Plants in the same condition o£ 

 shade, but in well-drained soil attained heights of two and a half to 

 three and a half feet, with darker green, or somewhat reddish stems, 

 and chasmogamous flowers. Conclusions derived from observation of 

 field conditions are that under the optimum condition for vegetative 

 growth both kinds of flowers are rare; under conditions optimum for 

 the production of chasmogamous flowers, cleistogamous flowers are 

 produced in abundance in the early moister part of the season and more 

 sparingly throughout the season ; under adverse conditions of drought or 

 toxicity of bog soil only, or chiefly, cleistogamous are produced. 



Goebel (16) pei formed a series of experiments upon several plants 

 including Impatiens noli-tangere to determine the conditions of produc- 

 tion of cleistogamous flowers. He planted Impatiens noli-tangere 

 seeds in pots of earth and sand. Some of the sand pots he watered 

 with nutrient solutions. The plants in earth produced both chasmo- 

 gamous and cleistogamous flowers; those in sand, only cleistogamous. 

 Those watered with nutrient solution produced more abundant cleisto- 

 gamous flowers, but no chasmogamous. He reported that plants of 

 this species, attacked by Sphaerolheca Castagnei and suffering loss of 

 leaves in July while in chasmogamous flower showed on August 11th 

 only cleistogamous flowers, while healthy plants of the species were 

 still in chasmogamous flower. He cites also lighting and high tem- 

 perature as leading to the production of cleistogamous flowers. 



My own experiments on cleistogamous flowers aimed to determine 

 the production of the two kinds of flower under adverse conditions of 

 drought, nutrition, leafage and temperature. Young plants averaging 

 3.5 dm. in height were transplanted from the woods to pots on May 

 29th. Plants were marked in the woods to serve as controls. To test 

 the effect of drought eight pots were selected, four in rich soil and four 

 in white sand. These were watered sufficiently to keep the plants on 

 the point of withering. One plant in sand died within a week without 

 producing flowers; one died within two weeks after producing a few 

 cleistogamous flowers; two continued to live for a month producing 

 cleistogamous flowers sparingly. Of the plants in the soil one died 

 in a few days without flowers; two died before the end of the third week 

 after producing a few cleistogamous flowers; one lived over a month 



