COOK AND COLLINS—ECONOMIC PLANTS OF PORTO RICO. L511 
takes a fine polish and is nsed in making rollers for casters and various utensils. 
The resin exuded from the stem called *‘ gnaiacum ”’ is said to have the property 
of changing color when brought in contact with various substances, also used as 
a stimulant in medicine. (Stahl, 2: 173.) 
A wild tree inet with on the coasts, reaching a height of 45 or 50 feet (14 or 15 
meters), with a trunk 12 to 15 inches (30 to 87 centimeters) in diameter. It fur- 
nishes a very hard wood, very fine-grained and compact. The sapwood which is 
almost as hard as the heart is light yellow, while the heart is brown mixed with 
green with darker stripes. It is a valuable wood and its exportation forms ¢ 
branch of commerce. It cuts well with the saw and in spite of its fibrous texture 
is much worked. It can also be split, especially when recently cut, at which 
time the wood is much softer and more easily worked. It becomes much harder 
on exposure to the atmosphere and is then very difficult to work. 
It is used extensively for machinery and in cabinet work and for turned articles, 
and in all works where strength and hardness are needed, such as wooden cogs, 
mortars, hubs of wheels, etc. It is susceptible of a high polish. The green wood 
has a specific gravity of 1.080; the dry, 1.554 to 1.360.) (Grosourdy, 2: 389.) 
It is believed in Porto Rico that coffee powdered with a mortar and pestle of 
“onayacan ”’ is far superior to that ground in a wooden mill. | 
Guajacum sanctum. GUAYACANCTLLO. 
Family Zygophyllaceae; a tree said to have been abundant formerly on the 
coast hills of the south side of the island, but now nearly exterminated as far as 
large trees are concerned. The wood is considered valuable. and a resin or balsam 
exuded from it is medicinal. (Stahl, 2: 174.) 
According to Engler and Prantl the wood of this species is also utilized in com- 
merce as lignum vitae. 
Guajanilla amarilla. 
A wild tree produced in abundance in the southern part of the island. Its 
height is about 40 feet (12 meters), and its trunk 12 to 15 inches (30 to 87 centi- 
meters) in diameter. The wood is strong, dark yellow. breaking with a vertical 
fracture. Its most common use is for shelving in houses. (Grosourdy, 2: 386.) 
Guajanilla prieta. 
Said to be a variety of guajanilla amarilla, distinguished only by having its 
dark yellow wood streaked with brown. (Grosourdy, 2: 586.) 
Guajanillo. 
Captain Hansard gives the specific gravity as 0.80 and states that it is the same 
as “ caracolillo.” 
Guajona. 
A large tree occurring rarely in the mountains of the Luquillo region; the 
wood makes good boards. The name means gypsy. (Hansard. ) 
Gualteria americana. See Waltheria indica. 
Guamé. See Jnga laurina. 
Specific gravity, 0.70 (Hansard). Used for firewood and as a coffee shade. 
The fruit is a broad, bean-like pod with edible, rather sweet-tasting, fluffy pulp. 
Abundant in foothills. 
Guandabana. 
Soursop. The fruit of Anona muricata. 
Guanabancilla cimarrona. See Vincetowricum, 
Guanabanillo. 
A tree from all parts of the island; height, 20 to 25 feet (6 to 7.5 meters): diam- 
ter, 10 to 12 inches. Wood light, soft; specific gravity, 0.728; not used. (Exp. 
1857.) 
