486 BHIZOCARPE^. (pepper WORT FAMILY.) 



1. S. rupestris, Spring. Stems prostrate or ascending, rather rigid, 

 2 to 12 inches long, vaguely or subpinnately branching : leaves glaucescent, 

 closely imbricated and appressed, lanceolate, scarcely a line long, convex and 

 grooved on the back, bristle-tipped and ciliate : spikes strongly quadrangular : 

 macrosporangia abundant, intermixed with the slightly smaller and more 

 numerous microsporangia. — On dry rocks, especially in the mountains. 



Subclass IL ISOSPOKE^ 

 Producing but one kind of spore. Leaves without ligules. 



Order 93. L.ycOPODIACE^, (Club-Moss Family.) 



Moss-like plants, with small leaves imbricated in 4 to many rows 

 on the pinnately or dichotoinously branching stems, and (in ours) M'ith 

 reniform 1 -celled sporangia in the axils of bracts forming stalked or 

 sessile spikes. 



1. L Y C O P O D I U M, L., Spring. Club-Moss. Ground-Pine. 



Characters those of the order. In ours the leaves (bracts) of the spike are 

 yellowish, ovate or heart-shaped, very different from the other leaves. 



1. L. annotinum, L. Stems prostrate and creeping, 1 to 4 feet long; 

 the ascending branches similar, dichotomous, 4 to 6 inches high : leaves in 

 several ranks, equal, spreading, rigid, lanceolate, pointed, serrulate, 2 to 

 4 lines long: spikes solitary at the ends of leafy branches. — From Colorado 

 to Washington, eastward and northward across the continent. 



Class II. FILICIN^ 



Plants with a solid stem, which (in ours) is horizontal 

 and usually underground, bearing broadly expanded mostly 

 long-petioled leaves {fronds), with prominent midrib and 

 veins. Prothallus monoecious. 



Order 94. KHIZOCARPE^. (Pepperwort Family.) 



Aquatic plants, with a horizontal stem floating upon the water or 

 running through the mud at the bottom of shallow water : leaves cir- 

 cinately developed, simple or quadrlfid : spores of two kinds : the fruits 

 (conceptacles) borne on peduncles (in fact petioles^, or sessile beneath 

 the stem. 



