712 SYSTEMATIC BOTANY. 



{figs. 1090 and 1091). — Character. — Herbaceous plants, 

 usually resembling Mosses, with creeping stems {fig. 1090) and 

 forked ramification {fig. 10); or aquatic plants with corm-like 



Fig. 1090, 



Fig. 1090. Lycopodium innvdatum. Marsh CIuh-Moss. The stem is creeping, 

 and bears numerous small sessile imbricated leaves. 



Stems {fig. 1091). Leaves sessile, usually small and imbricated 

 {fig. 1090), sometimes tufted {fig. 1091) and linear-cylindrical 

 {fig. 1091). Fructification in the axils of leaves {figs. 798 and 

 799), or immersed in their substance, often spicate {fig. 10) : 

 consisting of either one kind of sporangium only, called the pollen- 

 sporangium ; or commonly of two, called oosporangia {fig. 801), 

 and pollen-sporangia {fig. 800). The 'poUen-s'porangia {fig. 800) 

 contain a number of small pores {microspores) ; and the oospo- 

 rangia enclose 4 large spores {macrospores) {fig. 801). (See 

 pages 365 and 366.) 



Distribution, ^c. — They are almost universally diffused, oc- 

 curring in cold, temperate, and warm climates. Examples of 

 the Genera: — Lycopodium, Isoetes. There are about 200 species. 



Properties and Uses. — Many species contain an acrid prin- 

 ciple. In moderate doses they are frequently emetic and pur- 

 gative, but in large doses they sometimes produce poisonous 

 effects. Some are reputed to possess aphrodisiac properties. 

 The spores of several are inflammable. 



