38 TREE ANCESTORS 



its sites, and modified by the great extension of organized culti- 

 vation of bananas, cane, coffee, rubber, citrus fruits, etc. 



These three regions are the Costa Rican, Guatemalan and South 

 ]\[exican Gulf regions. The Costa Rican region comprises Panama, 

 Costa Rica and southern Nicaragua. Vast and dense tropical rain 

 forests or impenetrable jungles once covered the Atlantic water- 

 shed, which includes most of the area since the divide is near the 

 Pacific coast. Many South American types are present, as for 

 example, Podocarpus (taxifolia and salicifolia) which replaces the 

 pines of the mountains of Guatemala. Oaks are still abundant 

 above 7000 feet, but most of the North American broad leaved 

 types that are represented reach their southern lunits in Costa 

 Rica. The rain forest is dense and almost infinitely varied — the 

 trees with buttressed roots, the undergrowth thick, and a great 

 variety of lianas and epiphytes. Some of the commoner trees are 

 Ceiba, Hura, Cedrela, Haematoxylon, Erythrina, Guaiacum, 

 Castilloa, Achras, Pithecolobium, Leucaena, Inga, Ficus, etc., 

 with a great variety of palms. 



The Guatemalan region, which includes the state of Cliiapas 

 (Mexico), Honduras, Salvador, Guatemala, and northern Nicara- 

 gua, is similar to the preceding except that the oaks are more 

 abundant in the uplands and pines replace the podocarps. The 

 rain forest, rich in species and with a great diversity of palms, 

 contains many valuable species destined at some time to be of 

 much more commercial value than has as yet been realized. The 

 northward extension of this forested area along the Gulf coast of 

 Mexico reaches to about Tuxpan, and it is practically identical in 

 character with that of the lands farther south. The climate is 

 hot and wet, the vegetation evergreen and dense. The mangrove 

 swamps of the lagoons are replaced inland by the jungle except 

 where it has made way for banana, cane, rubber, mango, and other 

 cultivated crops. This is the center of the vanilla industry. Above 

 2000 feet small oaks appear, becoming more prominent with in- 

 creasing altitude until at about 6000 feet evergreen oak forests 

 with a tropical undergrowth are typical. At about this elevation 

 pines mingle with the oaks and above 7000 feet the pines pre- 

 dominate. 



