3864 USEFUL PLANTS OF GUAM. 
A large shrub or moderate-sized tree growing on tidal muddy shores and salt- 
water estuaries, with a spreading head and aerial roots descending into the mud 
from the stem and branches. Branchlets marked with close scars of fallen leayes 
and stipules; leaves opposite, entire, thick, with large interpetiolar, deciduous 
stipules inclosing the buds, oval, acute at both ends, usually with a strong brown 
point at the apex, glabrous, bright green, pale beneath and dotted with minute red 
spots, 11.5 to 12.5 em. long; petiole 12 to 75 mm. long, stout; stipules 5 em. long, 
glabrous, soon falling; flowers moderate-sized on short, very thick peduncles, usually 
2 pairs together at the end of stout peduncles from axils of leaves of the same vear, 
ach flower supported by two hard, thick connate bracts; calyx segments 4, persistent, 
enlarged in fruit, pale yellow; petals 4, white, narrow, obtuse, curved, thick, indu- 
plicate, hairy within; stamens 8 (or 12), anthers nearly sessile, with numerous cells: 
ovary half-inferior, 2-celled, with two ovules in each cell: fruit ovate-conical, pendu- 
lous, slightly rough, dark brown, crowned by the reflexed limb of the calyx, 
I-seeded by abortion; seeds germinating on the tree, the radicle elongating and 
perforating the apex of the fruit, attaining a length of 45 em. or more before falling 
into the mud. 
The fruit of this species is not eaten in Guam. In some countries it is prepared 
by boiling, and ashes are applied to neutralize the bitter taste, after which it is 
baked and eaten. The bark is used for tanning, and yields a chocolate-colored dye, 
The sap is used for preserving fish nets, The wood is excellent. for: fuel, especially 
for baking. On the Malay peninsula mangrove sWamps are sometimes leased to 
woodcutters, who supply fuel to steamers and factories. The heartwood is of a dark 
red color, with dark rings of growth, and is durable, very hard, and heavy. It is, 
however, very brittle, and warps and cracks so easily as to unfit it for cabinet use. 
The sapwood is of a bright yellow color. The wood is durable in water and under- 
ground, and would be suitable for foundations of bridges and wharves. 
Mangrove swamps oceur in Guam at the mouths of Inany streams, especially on 
the shores of the harbor of San Luis de Apra. The native name as given by Gaudi- 
chaud, ‘“tonbog’’ or “tounboug,’’ is obsolete and only the Spanish name as given 
above is applied to it. It is interesting to note that the Visayan name of an allied 
species given by Padre Blanco, ‘‘tontog,”” is practi cally identical with the vernacular 
name for this species, ‘tongo,’”? on the remote islands of Samoa, where in like man- 
ner we have ‘niu’? for “niyog’’ (coconut), and “ifilele” for “ifil”? ( Intsia bijuga). 
This species is easily distinguished from Braguiera qymnorhiza by its 4-parted 
flowers. 
REFERENCES: 
Rhizophora mucronata Lam.; Poir. Eneye. 6: 189. 1804. 
Rhizophoraceae. MANGROVE FAMILY. 
The true mangroves are represented by Bruguiera gymnorhiza and Rhizophora 
mucronata. 
Ribbon fern. See Viltaria elongata. 
Rice. See Oryza sativa. 
Ricinus communis. CASTOR-BEAN. 
Family Euphorbiaceae. 
Loca, NAMEs.—Agaliya (Guam); Tafgantafigan, Lansina (Philippines); Lama- 
papalangi (Samoa), 
This well-known plant was introduced in early times. It has spread over the 
island and is now well established. The oil obtained from its seeds is used medici- 
nally as a purgative and is much milder in its action than the allied tubatubu (Jatro- 
pha curcas), which is very drastic. The best oil is expressed from decorticated seeds 
without the assistance of heat. In India a lamp oil is made from a large-seeded 
variety by boiling or slightly roasting the seed, drying in the sun, removing the 
