ACROGEN^. 



707 



Leaves with circinate vernation (^fig. 1088). Fructification at 

 the bases of the leaves or petioles {fig. 1088), and consisting of 

 stalked vahiilar sporocarps {figs. 790, 793, and 794), enclosing 

 antheridia {fig. 791) and sporangia {fig. 792), which are either 

 contained in the same cavity {fig. 790) or in separate sacs {fig, 

 794). (See pages 372—374.) 



Distribution, Sfc. — They are widely distributed, but are most 

 abundant in temperate regions. Examples: — Pilularia, Mar- 

 silea. There are 4 genera and about 20 species. 



Properties and Uses. — Unknown, or of little importance. 



Natural Order 289. Ltcopodiace^. — The Club-moss Order. 

 — Herbaceous plants, usually resembling Mosses, with creeping 

 stems {fig. 1089) and forked ramification {fig. 156); or aquatic 

 plants with corm-like stems (fig. 1090). Leaves sessile, usually 



Fig. 1090. 



Fiff. 1090. IsoHtes lacustris. Lake Quill-wort. The stem is small and corm- 

 like, and bears its leaves, which are linear-cylindrical, in tufts. 



small and imbricated {fig. 1089), sometimes tufted {fig. 1090), 



and linear-cylindrical. Fructification in the axils of leaves 



{figs. 795 and 796), or immersed in their substance, often spicate 



z z 3 



