PLANT SOCIETIES 323 
lingers on for fifty or a hundred years, reaching meantime 
a diameter of not more than two inches, and then, on 
getting more light, shoots up into a large and valuable 
timber tree.! 
394. Epiphytes. — It is even easier for a plant to secure 
enough sunlight in a forest region by perching itself upon 
the trunk or branches of a tree than by climbing, as our 
wild grapevines and the great tropical lianas do. ‘There 
is a large number of such perched plants, or epiphytes, 
embracing species of many different groups of seed-plants 
and of spore-plants. The fern shown in Fig. 228 is a good 
example of an epiphyte. Instances among seed-plants are 
the so-called Florida moss (Plate IV) and orchids like 
those in Fig. 13. 
1See the Primer of Forestry, Part I, U.S. Department of Agriculture, 
1899, pp. 33-35. 
