The sweet potato generally lies flat on the ground and sends out long stems in all directions. Its leaves, as you can see, are more or less like morning-glory and bindweed leaves. Its flowers are also like morning-glories, though they are not so pretty. It has a habit of storing up quantities of starch and sugar in its roots. It does this, hoping to use the starch and sugar again as food in forming new shoots. But sometimes we step in and disarrange all these fine plans, for we, too, need starch and sugar as food, and we take the big sweet roots and eat them. People plant large fields of sweet potatoes, particularly in the South. So next time you eat a sweet potato, remember it is one kind of morning-glory which has given it to you. The sweet potatoes are no relation whatever to our common potatoes; they do not belong to the same family. The sweet potato is not the only useful morning-glory. There is the jalap, though if you have ever made its acquaintance you may differ from me as to its value; for however useful it may be from the doctor’s point of view, it certainly possesses properties which are quite the reverse of agreeable. It, too, forms large tubers, which it stores full of plant food, but it so happens that this particular plant food is not fit for human food. We put it to quite another use. In fact, jalap is used as a medicine. It grows very luxuriantly at Jalapa, or, as the Mexicans spell it, Xalapa, in Mexico, and that is the way it gets its name of jalap. In spite of its very disagreeable taste and beneficial effect upon sick people, the jalap is a lovely vine with beautiful deep pink flowers. If you saw it growing along the eastern slopes of the Mexican mountains you would never suspect it of being a medicine plant, and you _might_ not suspect it of being a convolvulus, since its flowers are flat instead of tubular in form. [Illustration: SCAMMONY.] Several members of the Convolvulus Family have the same medicinal properties as jalap, and one in particular, whose name is scammony, is very highly esteemed. It has an uncommonly bad taste, and its swollen roots are brought all the way from Syria and Asia Minor, not because of their bad taste, but because of their power as a medicine. The scammony, like the jalap, is a pretty plant in spite of its bad-tasting, medicinal roots. Most of the Convolvulaceæ have a milky, bitter juice,—even our pretty, harmless morning-glories,—and in the jalap and scammony this seems to be exaggerated in quality and quantity. A few of the Convolvulaceæ manage to make woody stems and become shrubs instead of vines. Two of these live on the Canary Islands, and their sap, instead of being nauseous and bad-smelling, has a delicate and delicious fragrance. People take the wood from root and stems and press out the oil to be used in making perfumery. Perhaps you know the odor of oil of rhodium. Whenever you smell it you are inhaling the fragrance from a Canary convolvulus.