310 CLEISTOGAMIC FLOWERS. Chap. VIII. 



size, as well as from the corolla being rudimentary, they 

 are singularly inconspicuous. Consequently insects do 

 not visit them; nor if they did, could they find an en- 

 trance. Such flowers are therefore invariably self-fer- 

 tilised; yet they produce an abundance of seed. In sev- 

 eral cases the young capsules bury themselves beneath 

 the ground, and the seeds are there matured. These 

 flowers are developed before, or after, or simultaneously 

 with the perfect ones. Their development seems to be 

 largely governed by the conditions to which the plants 

 are exposed, for during certain seasons or in certain 

 localities only cleistogamic or only perfect flowers are 

 produced. 



Dr. Kuhn, in the article above referred to, gives a 

 list of 44 genera including species which bear flowers 

 of this kind. To this list I have added some genera, 

 and the authorities are appended in a foot-note. I 

 have omitted three names, from reasons likewise given 

 in the foot-note. But it is by no means easy to de- 

 cide in all cases whether certain flowers ought to be 

 ranked as cleistogamic. For instance, Mr. Bentham 

 informs me that in the South of France some of the 

 flowers on the vine do not fully open and yet set 

 fruit; and I hear from two experienced gardeners that 

 this is the case with the vine in our hot-houses; but 

 as the flowers do not appear to be completely closed it 

 would be imprudent to consider them as cleistogamic. 

 The flowers of some aquatic and marsh plants, for 

 instance of Ranunculus aquatilis, Alisma natans, 

 Subularia, Illecebrum, Menyanthes, and Euryale,* 

 remain closely shut as long as they are sub- 



* Delpino, 'SulV Opera, la Dis- Flora,' vol. iii. 1825. p. 157. For 



tribuzione dei Sessi nelle Piante/ the behaviour of Menyanthes in 



&c. 1867, p. 30. Subularia, how- Russia see Gillibert in ' Act. Acad, 



ever, sometimes has its flowers St. Petersb.,' 1777, part ii. p. 45.— 



fully expanded beneath the water, On Eurvale ' Gardener's Chroni- 



see Sir J. E. Smith, 'English cle,' 1877, p. 280. 



X 





