CHAPTER XVI 



SPORE-BEARING PLANTS 



Vocabulary 



Complicated, not simple in structure. 



Parasite, plant or animal which obtains nourishment at the ex- 

 pense of another. 

 Scavengers, destroyers of waste matter. 



The majority of plants with which we are familiar obtain food, 

 grow and reproduce by root, leaf, flower, and fruit, just as we 

 have been learning, but there are a large number of important, 

 but less conspicuous, forms that have no flowers, and so produce 

 no seeds. These flowerless plants reproduce by single cells called 

 spores which, by a more or less complicated process, develop into 

 the plant again. 



Classification of Spore Plants. The simplest of these flower- 

 less plants are the algae, which may consist of only one cell as in 

 pleurococcus which forms the green coating often seen on stones, 

 bark, and old fences, or they may grow to large, many celled forms, 

 such as the sea weeds, or from the green mats of pond scum 

 (Spirogyra) that cover our ponds. The fungi are another large 

 group of spore plants which have no chlorophyll and hence have 

 to depend on other plants or animals for organic food. They are 

 parasites, and among them we find mushrooms, puff balls, moulds, 

 yeast, and bacteria. The next group, lichens, are really organisms 

 consisting of algae and fungi living together as one plant and are 

 familiar as the variously colored, flat, scaly forms that grow in 

 patches on rocks and trees. More familiar still are the mosses 

 forming the green carpet of the woods, and finally we come to the 

 largest and most complicated of the spore plants, the ferns and 

 their relatives, the horse-tails and ground-pines. 



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