L YCOPODIA CE^E. 1 3 5 



ing stout peduncles, 3' 5' long, with subulate bristle-tipped 

 bracts, producing 34 strobiles; leaves linear, acute, bristle- 

 tipped, entire, or minutely denticulate, those of the horizontal 

 stems strongly denticulate ; sporophylls deltoid, erose subulate- 

 tipped ; sporangia reniform. Pennsylvania to Minnesota, Ore- 

 gon, and northward. 



B. Leaves in five rows ; stems slender. 



13. L. Sitchense Ruprecht. Prostrate stems, 8' 12' long, 

 on the surface or a little buried, sending up frequent aerial 

 stems, which branch several (46) times to form compact 

 masses of vertical terete branches, 2' 3' high, with occasional 

 stronger strobile-bearing branches ; leaves lanceolate with a 

 broad base, spreading and curving upward, thick, entire, acute, 

 excurrent in five rows on the branchlets ; peduncles short (less 

 than 5"), very slender, with a few subulate bracts, or none, the 

 strobiles then sessile upon strong leafy branches; sporophylls 

 broadly ovate, erose, with long acuminate to subulate apices. 

 Labrador to New York, Idaho, Washington to Alaska. 



C. Leaves in four rows on flattened dor si-ventral stems. 

 i . Branches convex on both sides ; leaves all alike. 



14. L. sabinsefolium Willd. Prostrate stems creeping along 

 the surface, with numerous aerial stems which soon branch 

 3 4 or 5 times to form a loose clump of erect (or straggling) 

 dorsiventral branches; leaves subulate, slightly spreading, 

 curved upwards, with thin apices, in four rows on the flattened 

 terminal and subterminal branchlets, those of the lateral rows 

 thicker and more curved than those of the upper and lower 

 rows ; peduncles (5" 2' long), on stronger terete branches, 

 their subulate bracts whorled or scattered ; strobiles i' long, 

 with broadly ovate sporophylls with short acute apices ; spo- 

 rangia reniform. Northern New England, Ontario, and Prince 

 Edward's Island. 



2. Branches with imder surf ace flat or concave. 



15. L. complanatum L. Rhizomes extensively creeping 

 along the surface, the branches spreading out horizontally, 

 forming fan-shaped tufts ; leaves in four rows, those of the 

 upper and lateral rows, cuspidate, 'with spreading apices, 



