* 
230 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Furnishes a wood dark red in color, which on account of its great strength is 
used in the construction of houses and in carpentry work suitable to its small 
size. It is not very durable except in water, where it is practically incorruptible, 
especially when nearly submerged. Its most common use is to make a fine grade 
of charcoal, well adapted for heating the bake ovens; the leaves, or still better, 
the bark, serve to tan leather. Specific gravity, 1.028. (Grosourdy, 2: 400.) 
Rhoeo discolor. SANGRINARIA. 
Family Commelinaceae; a succulent herb with ensiform purple leaves and 
small white flowers; commonly cultivated. 
Rhynchosia. See Dolicholus. 
Rivina octandra. 
Family Phytolaccaceae; a trailing shrub, 4 to 6 meters high. (Grisebach.) 
Between Sabana Grande and Yauco, growing by roadsides. 
Roble. See Tabebuia rigida, Catalpa longisiliqua, and Tecoma pentaphylla. 
A tree from all parts of the island; height, 45 to 50 feet (13 to 15 meters); diam- 
eter, 15 to 20 inches (37 to 50 centimeters). Wood yellowish, rather hard; specific 
gravity 0.735; used for lumber. (Exp. 1857.) 
Of rather slender habit, reaching perfection on the hills; more like cedar than 
oak; much used for yokes for oxen and other minor purposes; specific gravity 
0.85. (Captain Hansard. ) 
In Spain this name means *‘ oak;’’ in Porto Rico it is applied to several trees 
belonging to the family Bignoniaceae. 
Roble amarillo. See Tecoma stans. 
Roble blanco. See Tabebuia pentaphylla. 
Roble colorado. See Tabebuia schumanniana.” 
Roble guayo. See Bourreria succulenta and domingensis. 
Roble prieto. See Tecoma barterii. 
Rondeletia arborescens. See Rondeletia inermis. 
Rondeletia inermis. CoRDOBANCILLO. : 
A new species recently described by Urban to replace R. arborescens and R. 
laevigata of Stahl, which were not correctly identified. An indigenous shrub or 
small tree belonging to the family Rubiaceae; generally distributed throughout 
the island. (Urban, Symb. 1: 416.) 
The variety latifolia is reported from near Lares, and the variety oblongifolia 
from near Cayey. 
Rocon. See Bixa orellana. 
Rolandra argentea. YERBA DE PLATA. 
A woolly composite herb, 60 centimeters high, found in dry, sandy pastures. 
(Stahl, 5: 108.) 
Rollinia longifolia. ANon. 
Family Anonaceae; a tree having a light, tough wood, resembling lancewood. 
The natives of Guiana and Brazil use it for making spears, according to the 
Treasury of Botany. 
Rollinia mucosa. 
Reported from Adjuntas. 
Rollinia multifiora. Corazon CIMMARRON. 
A wild tree 25 or 30 feet (7 to 9 meters) high, with a rather straight trunk 8 to 
10 inches (20 to 25 centimeters) in diameter. The wood is rather light and soft, 
fibrous in texture, moderately fine-grained. The color is a handsome dark gray. 
No known use in Porto Rico. Specific gravity 0.509. (Grosourdy, 2: 377.) 
The habitat of this species is given in Index Kewensis as Guiana. 
