58 



Such a type probably resembled Lycopodium sabinaefolium, rather 

 than L. alpinum, as Pritzel suggests, for the latter on account of 

 the trimorphism of its leaves and remarkably developed dorsi- 

 ventrality forms a species of extreme divergence, while L. sabinae- 

 folium has a far more generalized form. Of the radially symmet- 

 rical species, L. Sitchense would justly claim to lie close to the 

 original form from which the dorsiventral plants under discussion 

 have arisen. 



The degrees of specialization seen in the North American con- 

 tinental species may be expressed in the following linear series : 

 Lycopodium sabinaefolium, L. Chamaecyparissus, L. complanatum 

 and L. alpinum. 



Referring to the diagnosis of Section B, it may further be 

 pointed out that the leaves of the upper and lower rows are not 

 always appressed. The upper ones in L. alpinum and the lower 

 ones in L. Chamaecyparissus are indeed so. In L. complanatum 

 and L. sabinaefolium the leaves of both upper and under rows 

 are spreading. 



Under Section B, Pritzel places Lycopodium complanatum 

 and L. Fawcettii with L. Chamaecyparissus as a variety of L. 

 complanatum. The relation of these two last named plants has 

 been heretofore a matter of doubt, but the facts which have 

 already been set forth * would seem fairly to settle the question 

 so far as North America is concerned. f Here the two plants 

 may be found growing in exactly the same habitat, but still dif- 

 fering anatomically, in external features and in physiological 

 characters. The more obvious characters of the species L. com- 

 planatum are seen in the ultimate shoots which are distinctly 

 plagiotropous, much flattened dorsiventrally, with leaves of the 

 under row much reduced, spreading, and not emarginate. The 

 rhizome is above ground. The spores ripen at least as much as 

 four weeks later than those of L. Chamaecyparissiis, which has 



* Lloyd, F. E. Two hitherto confused species of Lycopodium. Bull. Torr. 

 Club, 26 : 559-S 6 7- 15 N. 1899. 



j" While at Kew during the past summer I saw the type of Lycopodhim tristachyum 

 Pursh, Fl. Am. Sept. 2: 653. 1814, and find that it is exactly the species separated 

 by Al. Braun many years later as L. Chamaecyparissus . The earlier name will there- 

 fore replace the later and another of Pursh' s species can be justified. — L. M. Under- 

 wood. 



