THE VARIETT OF PLANT LIFE 



93 



in Chapter 25. A third group of the Mycophyta is the Basidium- 

 Fungi which includes the bracket fungi and the mushrooms. 

 These produce spores on special structures known as basidia, 

 found on the "cap" of the common mushroom (figs. 24, 63). 

 The remaining group of the Mycophyta comprises the Li- 

 chens, unusual plants exemplifying a condition known as sym- 

 biosis. Part of the lichen body is composed of fungus filaments, 

 part of unicellular green algae. 



Fig. 63. — Common mushrooms include false chantrelle (A), shaggy mane (B) 

 and parasol mushroom (C). 



These two kinds of plants live amicably together, profiting 

 by each other's activities. Lichens are gray-green plants capable 

 of living on bare rock or tree trunks; and in damp cool climates 

 such as northern New England they form an abundant epiphytic 

 flora (fig. 64). 



The Leafy Spore Plants 



As was discussed in Chapter 2, the migration of plants to the 

 land was dependent upon the development of a body adapted to 

 terrestrial living conditions. Among existing land plants there is 

 considerable variation in the complexity of the vegetative and 

 reproductive organs, ranging from the inconspicuous mosses to 

 the woody seed plants. Those species which are grouped into 



