THE 



AMERICAN NATURALIST 



Vol. XLI March, 1907 No. 483 



STUDIES ON THE OPHIOGLOSSACE.^ 

 DOUGLAS HOUGHTON CAMPBELL 



The family of the Ophioglossacese comprises the three genera — 

 Ophioglossum, Botrychium and Helminthostachys, which are all 

 evidently related, but whose affinities with the other Pteridophytes 

 are not so clear, and there is a good deal of difference of opinion as 

 to where they should be placed. Most botanists agree that the 

 Ophioglossacese are related to the true ferns, but this view is not 

 universally accepted, although the results of the more recent in- 

 vestigations tend to strengthen this conclusion. 



The most marked feature of the family is the peculiar fertile 

 leaf segment or spike; and the present paper is mainly concerned 

 with the question of the morphologic nature of this sporophyll. 



During the past year the writer had an opportunity of collect- 

 ing a large amount of material of the 0{)hioglossacefe in Ceylon, 

 Singapore and .lava. 'V\\\> iiicliKled several species of Ophio- 

 glossum, one (if Hotrvchiiim, :ui<l the nionotypic Helmintho- 

 stachys, — so that it has been possil^lf To make a first-hand study 

 of all the genera belonging to the family. The following account 

 of the morphology of the leaf is ha-^cd nuiiiily \\\)on a study of 

 this material. 



'riii: MnKnioi.ocv ..r thk Si-ohuimi yi.i.. 



fertile portion of the snike is more or le.ss extensively branched, 



139 



