201 



A morphological Study of Juniperus communis 

 var. depressa 1 ) 



by 

 George E. Nichols, 



Instructor in Botany in the Sheffield Scientific School of Yale University. 



With 4 figures and plates VIII— XVII. 



During recent years considerable attention has been given by 

 a large number of investigators to the morphology of different 

 gymnosperms, so that at the present time the number of living 

 genera which have not been worked on to some extent is com- 

 paratively small Exhaustive studies, however, have as yet been 

 made in only a few cases. At the time when the present work 

 was projected (1906) practically the only accounts dealing with 

 the sporangia, gametophytes. fertilization, and embryo in any one 

 gymnosperm were those of Coker (1903 b) on Taxodium, and of 

 Miss Ferguson (1904) on Pinus. Noren (1904) andSludsky (1905) 

 had already published short preliminary papers dealing with the 

 morphology of Juniperus communis, but no investigations of this 

 species based on American material had ever been made. Since 

 there seemed to be considerable doubt among systematic botanists 

 as to the identity of the European J. communis with the American 

 var. depressa, it was thought worth while to make a detailed mor- 

 phological investigation of the American form. 



Material and methods. 



The writer is indebted to Dr. P. A. Eydberg for confirming 

 his determination of the plants from which material for study was 

 collected. Dr. Rydberg writes: "It is Juniperus communis depressa 

 of Gray 's Manual. This has been referred both to J. communis 

 and J. sibirica f= J. nana). I think, though, that it is distinct 

 from the typical forms of both species, but I am in doubt whether 

 it should be referred as a variety to either of them or be regarded 

 as a distinct species." It will be seen by a comparison of the 



*) A thesis presented to the Faculty of the Graduate School of Yale Uni- 

 versity, June 1909, in candidacy for the degree of Doctor of Philosophy. 



