28 BULLETIN 354, U. S. DEPARTMENT OF AGRICULTURE. 



singly or in small clumps on the open grass slopes and in narrow 

 strips along the watercourses.^ 



On the north side of the divide the virgin forest area near La 

 Isolina constitutes a possible remnant of this moist deciduous forest. 

 Here the tabanuco (69) is a prominent feature in the stand. Else- 

 where, as on the limestone uplands north of Lares, the moralon (15), 

 aceitillo (66), capa blanca (155), limoncillo (129), granadillo (124), 

 and other large trees are reported formerly to have been common. 

 Here, too, we should expect to have found the caoba (72). Some of 

 the rich forest growth was cut for fuel and building material, but 

 much of it is reported to have been cleared away by the "conuco." 

 The land here is now merely open grass land. 



In the "pepino" or "pit" country a homogeneous forest cover is 

 impossible. In the pit bottoms, which are now largely under culti- 

 vation to bananas and coffee, a high forest cover of the moist deciduous 

 type undoubtedly prevailed. The steep sides and summits of these 

 hills in many places even to-day present a well-wooded appearance, 

 though the occurrence of an occasional fair-sized tree in some par- 

 ticularly inaccessible place throws into contrast the main cover, 

 which is low and bushy and much like that of the dry deciduous 

 formation. Undoubtedly these rough crags have been cut over in 

 the past, but owing to their absolute uselessness for cultivation they 

 have escaped being burned over. 



EASTERN MOIST DECIDUOUS FORESTS. 



The moist deciduous formation of India and Qeylon contains most of their valuable 

 timber trees, such as teak {Tectona grandis), sal {Shorea robusta), satinwood (Chloroxy- 

 lon swietenia), ebony {Diosypros ebenum), trincomalie-wood (Berrya ammonilla), etc. 

 Near the coast a number of evergreen trees are found in mixture, as MimiLSops hexandra, 

 M. elengi, species of Memecylon, Pleurostylia wightii, Nephelium, Sapindus, etc. In 

 Australia this is a savanna forest and consists largely of acacias and eucalypts. 



In South America this formation more closely resembles the savanna than the rain- 

 forest type and is known locally as "campos," "llanos," "caatinga," etc. It is 

 important economically because of the rubber-yielding trees which grow within it, 

 the "ceara-rubber" tree or "manisoba" (Manihot glaziovii, M. dichotoma, M. piyau- 

 hensis, etc.) and the "para-rubber" tree {Hevea braziliensis), the former in the open 

 savanna forests of northern Brazil and the latter in the basin of the Amazon. 



Tropical Rain-Forests. 



Forest vegetation culminates in density and luxuriance of growth 

 in the rain-forests, the most extensive of the original forest forms, 



1 Fringing-forests. — Closely allied to both the moist deciduous and rain-forest formations are the 

 appropriately named fringing-forests or gallery-forests, mentioned, respectively, by Schimper and Broun, 

 dense tropical forests of unusual luxuriance occupying the banks of streams and rivers within dry regions. 

 They owe their luxuriance to the abundant moisture in the soil. Their extent back from the river thus 

 depends on the quantity and constancy of the stream flow and the modifying influence it is able to exert 

 on the adjacent soils. Such was the type of forest in all probability that riinter(see note, p. 21) referred 

 to particularly as occurring in the vicinity of Guayama. Remnants of these forests are to be seen to-day, 

 in many places bordering the south coast streams where they have not been destroyed to make way for 

 cane growing. The contrast between them and adjacent forests of tlie dry deciduous formation is very 

 striking. The rich forests of the Amazon are to a considerable extent of this type. 



