RHIZOPHORACEAE. 



266 



Family 6. RHIZOPHORACEAE Lindl. 



]Mangrove Family. 



Shrubs or trees, with terete branches and usually glabrous foliage. 

 Leaves usually opposite, leatherj^, with stipules. Flowers perfect, solitary 

 in the axils or in spikes, racemes, cymes or panicles. Calyx with 3 or 4 val- 

 vate sepals.- Petals as many as the sepals, 2-cleft or lacerate. Stamens 

 twice or four times as many as the petals, or rarely of the same number, 

 inserted at the base of a disk ; filaments short or elongated ; anthers 2-celled, 

 opening lengthwise. Ovary inferior, or partly inferior, usually 2-5-celled 

 or rarely 1-celled; styles united; stigmas sometimes lobed. Ovules 2 or 

 rarely 4 or more in each cavity, pendulous. Fruit leathery, crowned with 

 the calyx, indehiscent or tardily septicidal. The family consists of about 

 15 genera, containing some 50 species, natives of tropical and subtropical 

 regions. 



1. RHIZOPHORA L. 



Evergreen maritime trees, with an astringent bark, and stout pithy branch- 

 lets. Leaves opposite, entire; stipules elongated, interpetiolar, caducous. 

 Flowers cream-colored or yellow, 2 or several on forking peduncles. Calyx- 

 tube short, adnate to the base of the ovary, the 4 lobes leathery. Petals 4, 

 emarginate, leathery. Stamens 4-12, alternate with the petals; filaments 

 short. Ovary 2-eelled, half-inferior, produced into a fleshy cone. Stigma 2- 

 lobed. Ovules 2 in each cavity. Fruit pendulous, 1-eelled, leathery. Seed 

 solitary, germinating in the persistent fruit, the elongating radicle sometimes 

 reaching the ground before the fruit falls. Endosperm wanting. [Greek, 

 root-bearing.] Three known species, the following typical, the others natives 

 of the Old World tropics. 



1. Rhizophora Mangle L. Man- 

 grove. (Fig. 285.) A shrub or tree, 

 reaching a height of 30° or more, form- 

 ing impenetrable thickets by the greatly 

 elongating radicles of the embryo and 

 the numerous roots. Leaves 2'-6' long, 

 leathery, elliptic or elliptic-obovate, ob- 

 tuse, with a stout midrib; petioles 2"-8" 

 in length; peduncles J'-IA' long, 2-3- 

 flowered; pedicels stout, 2"-5" long; 

 bractlets scale-like ; calyx-tube fleshy, tur- 

 binate or campanulate, the lobes lanceo- 

 late, about 5'' long, involute, keeled 

 within, very firm, recurved at maturity; 

 petals pale yellow, linear or nearly so, 

 cleft at the tip, involute above the middle, 

 cobwebby along the edges; anthers 

 clustered around the style; fruit about 

 y long, curved, the radicle protruding 

 as a narrowly clavate pendent body. 



Common on the borders of salt-ponds, , . , ^. , , 



bays and lagoons. Native. Florida, the West Indies and tropica continental 

 America. Flowers in summer and autumn. The plant doubtless reached Bermuda 

 by floating Reproductions of photographs in the great mangrove swamp at Hungry 

 Bay are published on plates 22, 23 and 2h Fifteenth Report Missouri Botanical 

 Garden. 



