364 



an excellent cordage. A decoction of the bark is used by the 

 natives of tropical America as a febrifuge. 



The wood is very heavy, weighing 72.40 lbs. per cubic foot of 

 seasoned wood. It is very hard, tough, strong, and durable. It 

 is close-grained, and takes a beautiful satiny polish. The heart- 

 wood is dark-reddish-brown streaked with lighter brown; some- 

 times it is almost black. The sapwood is pale, with 40-50 sea- 

 sonal rings. The pith rays are thin and broad ; the ducts are open 

 and diflfuse. The following table will show the mechanical 

 properties of the wood : 



Specific gravity 1.617 



Percentage of ash 1 . 82 



Relative approximate fuel value 1 . 1406 



Coefficient of elasticity 165567 



Modulus of rupture 1207 



Resistance to longitudinal pressure 860 



Resistance to indentation 462 



The wood makes an excellent fuel. As it is not attacked by 

 teredos, it is sometimes used for w^harf pilings. It also has been 

 used for flooring. The mangrove, however, grows in situation ^^ 

 that render very difficult the cutting and transportation of the 

 wood, and it is of little commercial importance. 



The young branches are stout, terete, conspicuously marked by 

 the large, oval, slightly elevated leaf-scars. The leaves are oppo- 

 site and stipulate. The stipules are interpetiolar, lanceolate, 

 acute, 1.5-2 inches long, glabrous, light green, infolding the bud, 

 and deciduous as the leaf unfolds. The terminal bud is strong and 

 conspicuous. The leaves are 3.5-5 inches long and 1-2 inches wnde. 

 The petioles are 0.5-1.5 inches long, smooth, light green, anfi 

 flattened. The blade is oblong, oval, or elliptical. It is glabrous, 

 thick, and coriaceous. The apex is rounded or acute ; the base 

 is cunette, narrowing gradually. The margin is entire and slight- 

 ly thickened. The upper surface is dark green and very glossy ; 

 the lower surface is pale, but veinlets are rather obscure, reticu- 

 late. The leaves are persistent for 1 or 2 years. It is interesting 

 to note that the old leaves serve as water-storage organs. The 

 old, yellowish leaves are twice as thick as leaves wdiich have just 

 attained their full size, and the former are notably charged witli 

 water. 



The flowers are small, dull colored, and not particularly con- 

 spicuous. They are produced continuously throughout the year 

 in the axils of the young leaves. They are borne on stout 2- or 

 3-branched peduncles 1.5-2 inches long. Each pedicel is sub- 

 tended by a 2- or 3-lobed involucral cup at the end of the pedun- 

 cle. Each flower has 2 short bracelets united in an involucral cup. 

 The flowers are perfect, regular, and when fully expanded are 

 about 1 inch in diameter. The calyx is coriaceous ; lobes 4 ; 2-3 

 times as long as the turbinate, globose tube ; each lobe acute, 

 thickened at the margins and with a median rib on the inner sur- 



