iii PREFACE TO THE EEPEINT OP 1884. 



The following Acanthaceae have cleistogamic flowers : 

 Stenandrinm rupestre, DicUpetra asswrgens, Stemofia- 

 eanthus coccineus, Bicmthera sessilis, Blechum Broxmnei. 



Among other families : Briihalis ftuticosa, (Bvhia- 

 <xm), Polystachya luteold, are also cleistogamic. 



The curious flowers of Pavonia hastaia are described 

 by E. Heckel (' Comptes rendus,' IxXxix., p. 609). This 

 species has cleistogamic flowers, which chiefly difi'et 

 ih appearance from the perfect flowers, in having no 

 nectar-guides ; there are, as usual, no nectaries. The 

 pollen is entomophil(fus in character, and it is said 

 that the tubes are protruded while the pollen is in the 

 anthers. 



F. Ludwig CBot, Centralblatt,' 1880, p. 861) 

 mentions Plantago virginica as producing under cultiva- 

 tion only cleistogamic flowers. 



F. Miiller, ('Nature ' xix. 1879, p. 463) shows that the 

 curious submerged Podostomacese of Brazil produce 

 flowers which are probably cleistogamic. 



Solms Laubach, ('Gottingen JSTachrichten,' June 

 1882) has written an interesting paper on Heteranthera, 

 a plant belonging to the Pontedereaceae. He describes 

 the cleistogamy of some species of the genus, and 

 points out that the form and distribution of the cleisto- 

 gamic flowers serves as a specific character, without 

 which H. eallmfolia could not be distinguished from 

 H. Kotschyana. 



FeaNcis Dabwin. 



Jan., 1884:. 



