LEGUMINOUS PLANTS. 153 



and is considerably exported. It is a climbing plant, with tender 

 stalks, about 20 feet long. The root has singular horns ; is about a 

 foot in breadth, of a dark color externally, but white within. 



The winged yam (dioscorea-alata), is a species much cultivated, with 

 roots 3 feet long and often weighing 30 pounds. The species are 

 cultivated like the potato ; are planted in Aug. and dug in Nov. Hav- 

 ing apparently no buds, and sending out stems from any parts of the 

 surface, a portion of the skin is left on each piece planted. When 

 dug, the roots are dried in the sun, and placed in dry sand or casks. 



The yam is esteemed little inferior to the potato either in flavor or 

 nutriment. It is easy of digestion and palatable. The juice, like that 

 of many of the most valuable roots, before being boiled, is acrid and 

 irritating to the skin. The roots of some varieties are twisted like 

 serpents, or spread out like the hand and fingers. They arrive at 

 maturity sooner than the potato, but are raised in a similar manner. 

 Care is taken that they be not wounded when dug. 30,000 pounds 

 have been raised on an acre. 



The species are all vines,with heart-shaped leaves and small flowers. 

 One of these is common in our southern and middle states. No doubt 

 they might be cultivated here to great advantage. 



LEGUMINOUS PLANTS. 



This useful class of vegetables affords the 2d division of the farina- 

 ceous seeds, those of the cerealia constituting the first. Next to these 

 and the potato, they are the most important esculent vegetable in this 

 and most countries of Europe and Asia, both for man and the lower 

 animals. They are found in the tropical climate, even on dry and 

 otherwise unproductive soil. Their nutritive parts, or seeds, are with- 

 in 2 valved, oblong pods. 



Carbonic acid is said to be more abundant where these plants are 

 cultivated especially during their flowering, and that miners are made 

 fatally sensible of it. Those of this family of plants, not applicable 

 for human food, are much eaten by domestic animals; and they are 

 not only thus useful to the animal creation, but, by attracting moist- 

 ure from the atmosphere, they greatly aid in the growth of other 

 plants, the seeds of which are sown with them. They are therefore 

 grown together by the Hindoos, to be more certain of a crop of small 

 grain ; and, in the event of a drought, of a pulse crop. The tops, 

 from this circumstance, are observed to be fresh and green when the 

 bottoms are dead. The properties of the legumes are exceedingly 

 variable. Similar organs of species closely allied are often found to 

 elaborate very dissimilar principles, and the diatetical, medicinal or 

 poisonous properties therefore vary in a corresponding manner. Of 

 all the species of this genus the well known pea and bean are most 

 valuable. 



