KEYS TO GENERA AND SPECIES 



Division I. Pteridophyta. Ferns and Fern-allies 



1. Lycopodiaceae Rich. — Clubmoss Family 



1. Lycopodium L. — Clubmoss 

 1. Sporangia borne in the axils of foliar leaves, not in distinct ter- 

 minal cones. 



2. Leaves linear-oblanceolate, glossy, widest above the middle, 

 erose-denticLilate toward the apex; cool moist woods, rare 

 L. lucidulum Michx. 



2. Leaves lanceolate-linear, widest at the base, nearly or quite 



entire; cool woods, rare; Cook, La Salle, and Ogle counties 

 L. porophilum Lloyd & Underw. 



1. Sporangia borne in terminal cones; sporophylls similar to the 

 foliar leaves. 



3. Sterile branches creeping; Cook Co., L. N. Johyison in 1890; 



/. A. Steyermark in 1947 L. inundatum L. 



3. Sterile branches erect; shaded sandstone ledges; Pope Co., 



/. W. Voigt & J. R. Swayne 1170 



L. flabellijorme (Fern.) Blanch. 



2. Selaginellaceae Waxming 



1. Selaginella Beauv. — Selaginella 

 L Leaves numerous, uniformly imbricated, many-ranked, subulate, 

 short-awned; dry sandstone rocks, local; n. 111., extending 

 southward to Henderson and La Salle counties; also Pope Co. 

 Rock Selaginella ^. rupestris (L.) Spring 



1. Leaves of two kinds, 4-ranked, spreading in two planes, ovate, 



acute or cuspidate; moist soil, local. Creeping Selaginella 



iS". apoda (L.) Morren 



3. Isoetaceae Warming — Quillwort Family 



1. Isoetes L. — Quillwort 



L Megaspores 0.3-0.4 mm in diameter, nearly smooth, or with low 

 tubercles; microspores finely spinulose, ashy-gray; wet meadows 

 or shallow ponds, rare; has been reported from Cook, Fulton, 



Madison, McHenry, Menard, St. Clair and Stark counties 



/. nielanopoda Gay & Dur. 



1. Megaspores 0.4-0.6 mm in diameter, honeycomb-reticulate; 



microspores smooth or nearly so; ponds, rare. St. Clair Co 



/. engelmanni A.Br. 



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