148 CARROLL— ON DEVELOPMENT OF 



Impatiens pallida that the cleistogamous flowers appear in May and last 

 through June, a few lasting throughout the summer. Bennett* states 

 for Impatiens fulva that on the banks of a tributary of the Wey the two 

 kinds of flowers were "absolutely synchronous." Bennett quotes 

 Weddell as reporting for /. noli-tangere that the inconspicuous flowers 

 occur latest, and Mohl as reporting only cleistogamous in June, and 

 only chasmogamous flowers in September. He reports plants of /. 

 noli-tangere observed in the Botanic Gardens at Oxford on the last day of 

 September as having "abundance of cleistogenous flowers with half- 

 expelled corolla-cap, while scarcely any of the perfect flowers were met 

 with and these on different plants." The earliest date noted in the 

 vicinity of Philadelphia in 1916 for the appearance of cleistogamous 

 flowers in /. fulva was June 10 and in /. pallida June 13th. Bennett says 

 "I have never found the two kinds on the same branch, occasionally on 

 different branches of the same plant, but more often on separate plants. " 

 In southeastern Pennsylvania in both species the cleistogamous flowers 

 were found in abundance along with the chasmogamous flowers through 

 the entire summer until late September. In Potter County, Pa., and 

 in Algonquin Park, Ontario, both types of flowers were found in abun- 

 dance during August. Indeed one of the most noticeable facts about 

 the cleistogamous flowers is their universality. They are less abundant 

 in mid-summer on the taller and more vigorous plants, but on the ex- 

 tremely tall plants noted above chasmogamous flowers were also gen- 

 erally less abundant. Smaller plants bear the cleistogamous flowers 

 more abundantly, yet plants of average height growing under good 

 conditions were found to bear both kinds in fair abundance, the cleis- 

 togamous flowers appearing upon the shorter and lower branches. Even 

 in mid-summer careful examination of lower, short side-branches of 

 plants in full chasmogamous flower showed the presence of the cleis- 

 togamous flowers and fruit. 



Pseudocleistogamous Flowers 



In addition to the truly cleistogamous flower, an intermediate type, 

 or rather various intermediate grades between cleistogamous and chas- 

 mogamous, are to be found. Bennett says that he never noticed the 

 least indication of any intermediate condition between the two kinds 

 of flower (4 p. LS2). He states that Bentham and Boswell-Syme de- 

 scribe the two kinds of flowers as growing intermixed in the same raceme 

 in /. noli-tangere. I have found intermediate types in both pallida 

 a.nd fulva in the same inflorescences with normal chasmogamous flowers. 



