INSECTS 



for we have numerous representatives of them with us 

 today in those lowly evergreen plants known as club 

 mosses, whose spreading, much-branched limbs, usually 

 trailing on the ground, are covered by rows of short, 

 stiff leaves. The most familiar of the club mosses, though 

 not a typical species, is the "ground pine." This humble 

 little shrub, so much sought for Christmas decoration, 

 still in some places carpets our woods with its soft, broad, 

 frondlike stems. In the fall when its rich dark green 

 so pleasingly contrasts with the somber tones of the 

 season's dying foliage, it seems to be an expression of 

 the vitality that has preserved the lycopod race through 

 the millions of years which have elapsed since the days of 

 its great ancestors. The "resurrection plant," often sold 

 to housekeepers under false or exaggerated claims of a 

 marvelous capacity for rejuvenation, is also a descendant 

 of the proud lycopods of ancient times. 



In our present woodlands, along the banks of streams 

 or in other moist places, there grows also another plant 

 that has been preserved to us from the Carboniferous 

 forests — the common "horsetail fern," or Equisetum, that 

 green, rough-ribbed stalk with the whorls of slender 

 branches growing from its joints. Our equisetums are 

 modest plants, seldom attaining a height of more than a 

 few feet, though in South American countries some species 

 may reach an altitude of thirty feet; but in Carboniferous 

 times their ancestors grew to the stature of trees (Fig. 54) 

 and measured their robust stalks with the trunks of the 

 lycopods and giant ferns. 



Aside from the numerous representatives of these sev- 

 eral groups of plants, all more or less allied to the ferns, 

 the Carboniferous forests contained another group of 

 treelike plants, called Cordaites, from which the cycads 

 of later times and our present-day maidenhair tree, or 

 ginko, are probably descended. Then, too, there were a 

 few representatives of a type that gave origin to our 

 modern conifers. 



[88] 



