vrell-formed, and tall. It conimonly attains diameters of 3-U feet and 

 heights of lOO-l^O feet. Buttresses are usually small or lacking. 



The wood is generally comparable to .Greenheart in density and in mechani- 

 cal properties. Shrinkage values slightly exceed those of .;hite Oak and 

 the vifood is rather prone to checl^ upon vreathering. I'eai'twood of Bullet- 

 wood has long been recognized for its high re.sistance to decay and insect 

 attack. The National Park Service in Puerto' Fico has reported that timbers 

 of Ausubo ( iianilkara bidentata), still soand after more than liOO years 

 of service in buildings, have been re-used wion the reconstruction of 

 historical sites. The wood lacks resistance to marine borers. 



Bulletwood has a number of desirable characteristics that have resulted 

 in a wide variety of local uses including flooring, foundations, bridge 

 meibers, posts, poles, and railway ties. Its great strength, high wear 

 resistance, and durability recommend it for heavy and durable construction, 



3. Guayacan (Tabebuia guayacan, T. he terotr.ich a). r'ore than tyrenty specias 

 of Tabebuia have dark greenish-bro"m heartviood of high density, strength, 

 and durability. These species range from southern liexico through Central 

 America and South America as far south as y'rgentina. Tabebuia guayacan 

 and T. heterotricha are here referred to specifically, Tlie former occurs 

 in Genti'a.l ^im^rica, southern i.iexico, and Colombia; the latter from 

 Nicaragua to Venezuela. Guayacan trees are usually tall and straight, com- 

 monly 2-3 feet in diameter and 90-100 feet in height. The bole is cylindri- 

 cal and free of branches for lj.0-^0 feet. Heavy buttresses are usually 

 limited to the basal 3 feet. 



Except for the lower stiffness of Guayacan, this wood compares closely 

 with Greenheart in its mechanical properties. Density is slightly less 

 than that of Greenlieart. In shrinkage, Guayacan is similar to -hite Oak, 

 The Tfood is rated only fair in its resistance to the development of checks 

 ipon weathering. Guayacan heartvfood is extremely durable with respect 

 to decay and resistant to insect attack. It has been reported sound after 

 300 years' exposure ii^ Panama. 



Because of its durability and strength, Guayacan finds local use in house 

 construction, railway crossties, heav^'- construction timbers, mine timbers, 

 and marine construction. 



h. Muira-juba (Apul eia molar is). This species is one of the larger trees 

 of the Amazon valley forest of Brazil, sometimes exceeding l60 feet in 

 height with a large bole. A related species, Apuleia leiocarpa , having a 

 similar wood, is well knovm in Brazil and Argentina. liuira-juba attains 

 its best development and is riost com'i->only found on rich, moist but vrell- 

 drained, clay soils. 



The TQod is considerably lighter than Greenheart aiid correspondingly weaker 

 although its strength properties exceed those of most vfell-l'nown domestic 

 woods. Air-diy bending and crushing strengths and stiffness of Muira-juba, 

 for exaraple, are about 1|0 ]Der cent higher than corresponding values for 



