34 BULLETIN 3.54, U. S. DEPAETMEISTT OF AGKICULrURE. 



Among nonleguminous trees are guayacan (60), jobo (87), almacigo 

 (70), tea (64), guano (107), near (126), quebra hacha (94), and a host 

 of others. The ceiba (105) is a conspicuous tree of the open savanna.^ 



Old Field Growth. 



The old field type is an incidental and temporary one, in many 

 places in a formative state. It varies considerably from place to 

 place, the designation having been selected for all situations where 

 there is a manifest tendency of land formerly cultivated and now 

 more or less covered with grass to revert to forest. This tendency 

 is at present general except on some dry south coast situations. The 

 palm-studded hills most strikingly display this effort of nature to 

 restore the balance. Pahns, through their ability to grow in dry 

 situations, are to that extent admirably adapted to assume this 

 pioneer role. Then- poor reproductive capacity, with the possible 

 exception of the palma de sierra, renders them less aggressive than 

 they otherwise might be. Another conspicuous old field pioneer 

 growth is the poma rosa (133). The ''poma rosa" type is very con- 

 spicuously developed on the uplands between Cayey and Guayama 

 and in the vicinity of Aibonito. Natural reforestation even by this 

 apparently more aggressive tree is slow. This may be due in part 

 to a practice of successive clearings rotating this volunteer wood 

 growth with intermittent cropping to rice, beans, and the like. Cut- 

 ting for charcoal and for other uses also undoubtedly interferes. 



Cultural Forests. 



A description of the forests of Porto Rico would be incomplete 

 without mention of its cultural forests. They not only cover a con- 

 siderable acreage and are uniformly developed and kept up, but they 

 are the most conspicuous forest growth on the island taken as a 

 whole. 



COCONUT PALM GROVES. 



The palma de coco (4), or simply coco, is of uncertain origin,^ but, 

 however that may be, it has by one means or another been distributed 



1 One especially notable tree of this species near Ponce measures, according to Cook and Collins, 36 meters 

 (118 feet) in circumference 4 feet from the ground, following the sinuosities of the trunk. Herrera says of 

 the ceiba that it "has so great a shade that a strong man can not threw a stone across it. The tree is so 

 big that a carpenter whose name was Pantaleo made a chapel of one hollowed out, being so thick that 

 15 men holding hand in hand can not grasp it. " 



2 Cook ("The Origin and Distribution of the Coconut Palm," by O. F. Cook, Contributions from the 

 National Herbarium, Vol. VII, No. 2) scouts the currently accepted opinion that this species originated in 

 the Indian Archipelago and concludes: "The original habitat of the coco palm is to be sought in South 

 America, the home of all the other species of cocos and of most of the closely related genera." He likewise 

 controverts the common notion that the coconut originated as a strand plant, that the thick husk is an 

 adaptation to enable the dispersal of seed by ocean currents, and that even the seeds thus transported have 

 the ability to germinate and maintain themselves in competition with the other strand vegetation. "The 

 coco pahn," he says, "is unable to maintain an existence when subjected to the competition of the wild 

 vegetation of tropical shores and forests." And, finally, "the idea (that they can not thrive in undistinbed 

 nature) is recognized in the Cingalese proverb, ' The coconut will not grow out of the sound of the sea or of 

 human voices,' and in the belief held among the same people that the trees will not thrive unless ' you walk 

 and talk amongst them,' " 



