102 Underwood and Lloyd : Lycopodium 



\ 2. Lepidotis. 



\ 3. Diphasiittn 



even more true of South America, which is likely to yield species 

 yet unknown, as well as much more definite information about 

 many that are now only imperfectly known. 



Ail descriptions of structural characters are based upon material 

 prepared by boiling, and upon glycerin-jelly microscopic prepara- 

 tions, of which in all instances camera-lucida drawings were made 

 to a uniformly applied scale. 



The three sections of the genus Lycopodium that are repre- 

 sented in the American tropics may be distinguished as follows : 



Foliage leaves normally many-ranked, mostly uniform. 



Sporangia in the axils of unaltered leaves. \ I. Selago. 



Sporangia aggregated in distinct terminal strobiles whose bracts differ widely from 



the foliage leaves. 

 Foliage leaves 4-5-ranked, dimorphous ; stems strongly dorsiventral. 



§ 1. SELAGO 



The northern types of this group are familiar in the boreal 

 Lycopodium Selago and the more common Z. lucidulum of the 

 Northern States. L. porophihim is a more restricted and local 

 plant somewhat intermediate between the other two species. The 

 tropical representatives are more numerous, a very few simulating 

 the northern species in habit, while a much greater number become 

 epiphytic and are pendent from trees. The species * of meridional 

 America may be separated as follows : 



Plants with radial symmetry ; leaves not twisted. 

 Plants terrestrial in habit. 



Leaves short, I cm. or less long. 



Plants erect or ascending ; leaves rigid. 



Leaves in 16-20 ranks ; stems short and rather stout. 

 Leaves serrulate, strongly hooked at the ends. 



5. Z. demi folium. 

 Leaves straight, with entire margins. 4. Z. Sieberianum. 



Leaves in 8 ranks, serrulate ; stems elongate. 

 Leaves reflexed or loosely spreading. 



Leaves verticillate, distant, closely coiling when dry. 



3. Z. polycarpum. 

 Leaves scattered, crowded, reflexed- spreading ; sporangia 

 1.2 mm. wide. I. Z. rtjlexutn. 



* A number of the species from South America are omitted here, owing largely to 

 lack of sufficient material. The following members of this group are more or less per- 

 fectly represented in the herbarium of the New York Botanical Garden in addition to 

 the species tabulated below : Z. compaction Hook., Z. rufescens Hook., Z. erythraeuvt 



Spring, Z. Mragonum Hook., Z. crassum H.B.K., Z. Hartwegianum Spring, L.fiU- 

 forme Sw. 



