980 



MANGIFERA 



than the ovary; petals inserted at the base of the disk, 

 5, rarely 4, with 1-5 veins, which are prominent on the 

 upper side but scarcely so at the apex; fertile stamens 

 1-2, inserted at the base of the disk. B. M. 4olO. 



W. M. 



MANGO. 



gifera. 



Consult Man- 



MANGOSTEEN. 



cinia Mangostana. 



Gar- 



1T362. The beginning of germi 

 nation in the Mangrove. 



MANGROVE (probably an 

 altered Malayan ibarne) is a 

 name applied to species of 

 Khizophora (Greek, root- 

 bearing). The Rhizophoras 

 are perhaps 5 or 6 in num- 

 ber, and are widely distri- 

 buted on tropical shores. 

 The genus gives name to 

 the family JRhizophoracece , 

 which Bentham & Hooker 

 place in close relation to 

 the Combretacece and Myr- 

 tacecn. The common Man- 

 grove, JR. Mangle, Linn., is one of the commonest 

 plants on the swampy shores of tropical and subtropi- 

 cal seas. It is not in cultivation, but its strange meth- 

 ods of propagation make it one of the most interesting 

 of plants. The following account is reprinted from 

 Bailey's "Lessons with Plants:" 



The Mangrove grows on the low shores of tropical 

 lands. It extends as far north as the twenty-ninth par- 

 allel in Florida, and occurs at the mouth of the Missis- 

 sippi and on the coast of Texas. It is a spreading bush, 

 reaching a height of 15 to 25 feet upon the shores, but 

 becoming a tall tree in various places. It is an- important 

 agent in the extension of land into the sea. The means 

 by which this result is accomplished are two. The fruit 

 is small and capsule-like, but does not fall from the tree 

 at maturity. A fruit is shown natural size in Fig. 1362. 

 The seed is germinating, sending its caulicle out through 

 the apex of the fruit. In Fig. 1363 the germination is 

 further progressed. In Fig. 1364, germination is nearly 

 completed. The seed has endosperm. The cotyledons do 

 not unfold in germination, but a woody tube grows from 

 them and projects from the fruit to the point a. Inside 

 this tube is the plumule. The hypocotyl continues to 

 elongate, becoming thick and heavy at its lower end. 

 When 6 inches or a foot long, it breaks away from the 

 joint a, carrying the liberated plumule with it, and strikes 

 root-end down in the mud. Roots push out from the 

 lower end, and the epicotyl rapidly elongates and rears 

 itself above the water. A piece of a Mangrove branch is 

 shown natural size in Fig. 

 1365. An aerial root is push- 

 ing through the thick bark. 

 The root makes a strong 

 curve when it strikes c^ the 

 branch, and then grows di- 

 rectly downward towards the 

 water. The branch from which 

 it springs may be only a few 

 inches above the water, or it 

 may be 10 feet; but the root 

 pushes on until it inserts it- 

 self in the mud, and there 

 makes a root system of its 

 own. These long, lithe, de- 

 scending roots (Fig. 1366), 

 swaying in the wind, are char- 

 acteristic features of the Man- 

 grove swamp. Usually the 

 hanging roots are un- 

 branched, but now and then 

 the tip breaks up into short 

 branches (Fig 1367) before it reaches the water. These 

 long roots remain attached at the upper end, and become 

 trunks. The Mangrove plantation, therefore, becomes 

 an interwoven mass, and thus marches on into the tidal 

 rivers and the ocean, catching the flotsam and jetsam of 

 the sea; and thereby it builds land and extends the 



1363. 



The hypocotyl 

 enlarging. 



MANIHOT 



shores. In the quiet recesses of the Mangrove swamp 

 aquatic and amphibious life finds refuge. The shell-fish 

 cling to the trunks and at low tide they are exposed, thus 

 giving rise to the stories of the early explorers that 

 oysters grow on trees. All this will recall the accounts 

 of the banyan tree, and there are wild fig trees (the 

 banyan is a fig) in Florida and southward which behave 

 in a similar way. It seems strange that roots should 

 strike out into the air, but the reader may have observed 

 the "brace roots" near the ground on Indian corn; and 

 many plants, as the ivy and trumpet-creeper, climb by 

 means of roots. 



1364. The hypocotyl nearly 

 full grown. 



MANIHOT (native Brazilian name). JZtiphorbiclcece. 

 About 80 species of perennial herbs or shrubs, wit 

 milky juice, occurring in tropical America, mostly in 

 Brazil. Nearly always smooth and blue-green colored: 

 Ivs. alternate, entire or palmately lobed or divided: 

 fls. large for the order, racemose or paniculate, termim 

 or axillary, monoeceous; calyx imbricate in the bud, 

 campanulate or radiate, often petal-like, 5-lobed; petals 

 none; stamens few, in 2 whorls in the angles of the 

 disk: capsules 3-celled, 3-seeded. Not much grown in 

 greenhouses, except in forms of M.palmata. The eco- 

 nomic species may do well in the tropical parts of the 

 United States, where they are being introduced. Ac- 

 cording to Nicholson, they are best grown in peat loam 

 and sand, and propagated by cuttings of young, rather 



