Selfbow

With reſpect to a bow being made round, we muſt recollect, that [Roger] Aſcham ſpeaks of a ſelf'''-bow; which, it ſeems, was made round as well as the back as in the belly: but back'd-bows have almoſt always a flat back, to prevent their caſting.

Source: wiktionary

Many Archers use a piece of waxed cloth, which is of great utility, as it not only gives the Bow a polish, but is a preventative against damps penetrating; this precaution however, is not so much required for self Bows, as backed ones. Self Bows are made of one piece of wood only, and that is generally of yew, but the long known difficulty of procuring good English yew, has compelled Bow makers of late years, to resort to various other woods, all containing great spring, but little pliability; the deficiency of the latter is amply supplied by the addition of a slip of ash, or some other tough wood glued to them; the toughness of the one combined to the elasticity of the other, both acting in conjunction, make capital Bows, and these it is that are called back'd Bows.

Source: wiktionary

[A] backed bow does not exceed a self bow, except that it is thought by some to be pleasanter and easier to draw, especially in the last inch, and of quicker cast.

Source: wiktionary

I once made a beautiful self-bow from a large branch of yew, which was amputated, after two valuable coach-horses had been poisoned by feeding on its leaves.

Source: wiktionary