a genus of the order of dioecia, belonging to the polygamia class of plants. There is but one species, viz. The aquatica, or water-tupelo-tree. This has a large trunk, especially near the ground, and grows very tall. The leaves are broad, and irregularly notched. The flowers come out from the sides of the branches, on footstalks of three inches long, and are of a greenish colour. The grain of the wood is soft and spongy; but the roots much more so, approaching near to the consistence of cork; and are used for the purposes of cork in Carolina, where these trees are natives. They grow in wet places, and usually in the shallow parts of rivers.

O

O, The 14th letter and fourth vowel of our alphabet; pronounced as in the words nose, rose, &c.

The sound of this letter is often so soft as to require it double, and that chiefly in the middle of words; as goose, reproos, &c. And in some words this oo is pronounced like u short, as in flood, blood, &c.

As a numeral, O is sometimes used for 11; and with a dash over it thus, ō, for 11,000.

In the notes of the ancients, O. CON. is read opus conductum; O. C. Q. opera conficiens; O. D. M. operæ, donum, manus; and O. LO. opus locatum.

In music, the O, or rather a circle, or double O, is a note of time, called by us a semi-breve; and by the Italians, circolo. The O is also used as a mark of triple time, as being the most perfect of all figures. See Triple.