328 CLEISTOGAMIC FLOWERS. Chap. VIII. 



were thrown up by some plants in my green-house 

 bore only cleistogamic flowers. The petals of small 

 size remained permanently closed over the repro- 

 ductive organs, but their white tips could just be 

 seen between the almost completely closed sepals. 

 The pollen, which was scanty in amount, but not so 

 scanty as in Viola or Oxalis, remained enclosed 

 within the anthers, whence the tubes proceeded and 

 penetrated the stigma. As the ovarium swelled the 

 little withered corolla was carried upwards in the 

 form of a cap. These cleistogamic flowers produced 

 an abundance of seed. Later in the season perfect 

 flowers appeared. With plants in a state of nature the 

 flowers open only in the early morning, as I have been 

 informed by Mr. Wallis, who particularly attended to 

 the time of their flowering. In the case of D. Anglica, 

 the still folded petals on some plants in my green- 

 house opened just sufficiently to leave a minute 

 aperture; the anthers dehisced properly, but the 

 pollen-grains adhered in a mass to them, and thence 

 emitted their tubes, which penetrated the stigmas. 

 These flowers, therefore, were in an intermediate con- 

 dition, and could not be called either perfect or cleis- 

 togamic. 



A few miscellaneous observations may be added with 

 respect to some other species, as throwing light on our 

 subject. Mr. Scott states * that Eranthemum ambi- 

 guum bears three kinds of flowers, — large, conspicuous, 

 open ones, which are quite sterile — others of interme- 

 diate size, which are open and moderately fertile — and 

 lastly small closed or cleistogamic ones which are per- 

 fectly fertile. Buellia tuberosa, likewise one of the 

 Acanthaceae, produces both open and cleistogamic flow- 



* ' Journal of Botany,' London, new series, vol. i. 1872, pp. 161-4. 





