.'i(')4 IISEFUL PLANTS OF GUAM, 



A hiiyo shrill) or moderate-sized tree prntwing nn tidal muddy shores and salt- 

 water t'stuarit'N, wilh a ^^ll^•adiIl^; head and aerial roots descending into the nuul 

 from tiie stem and l)ranelies. iiranclilets marked witii close scars of fallen leaves 

 and stipules; leaves opposite, entire, tiiick, witli large interpetiolar, deciduous 

 stipides inclosing the buds, oval, acute at both ends, usually with a strong brown 

 jioint at tiie aju-x, glabrous, bright green, pale l)eneath and dotted with miiuite red 

 spots, ll.o to 12.r) cm. long; petiole 12 t() 75 mm. long, stout; stipides 5 cm. long, 

 glabrous, soon falling; Mowers moderate-sized on short, very thick ]iedniicles, usually 

 2 jiairs together at the end of stout pedinicles from axils of leaves of the same year, 

 each flower supporti'd by two hard, thick connate bracts; calyx segments 4, persistent, 

 enlarged in fruit, pale yellow; ])etals 4, white, narrow, obtuse, curved, thick, indn- 

 plicate, hairy within; stamens 8 (or 12), anthers nearly sessile, with numerous cells: 

 ovary half-inferior, 2-celled, with two ovules in v.ar]\ cell; fruit ovate-conical, jiendu- 

 lous, slightly rough, dark brown, crowned by the retlc^xetl limb of the calyx, 

 1-seeded by abortion; seeds germinating on the tree, the radicle elongating and 

 l)erforating the apex of llu' fruit, attaining a length of 45 cm. or more before falling 

 into the nmd. 



The fruit of this species is not eaten in (J uam. 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 occur in Guam at the months of many 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, "tf)ntog," is jiractically identical with the vernacular 

 name for this sjjecies, "tongo," on theremote islands of Samoa, where in like man- 

 ner we have "niu" for "niyog" (coconut), and "ifilele" for "ifil" {Tntsia bijmja). 

 This species is easily distinguished from Bniguiera gi/iiniorhiza by its 4-parted 

 flowers. 



References: 



Rhizophora mucronata'LsLm.; Poir. Encyc. 6: 189. 1804. 

 Rhizophoraceae. Mangrove family. 



The true mangroves are represented by Bruguiera gymnorhiza and Rhizophora 

 ri>)irfO)i(itit. 



Ribbon fern. See VUtaria elongata. 



Rice. See Oryza saliva. 



Ricinus communis. Castor-bean. 



Family Euphorbiaceae. 



Local names. — Agaliya (Guam); Tafigantafigan, Lansina (Philippines); Lama- 

 papfdangi (Samoa). 

 This well-known i)lant 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 ])urgative and is nuich milder in its action than the allied tubatubu {Jatro- 

 pha cnraiH), 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 roa.sting the seed, drying in the sun, removing the 



