bark (redirected from elm bark)

bark, sailing vessel

bark or barque (both: bärk), sailing vessel with three masts, of which the mainmast and the foremast are square-rigged while the mizzenmast is fore-and-aft-rigged. Although the word was once used to mean any small boat, later barks were sometimes quite large (up to 6,000 tons). In addition to the standard three-masted bark there are also four-masted barks (fore-and-aft-rigged on the aftermast) and barkentines, or three-masted vessels with the foremast square-rigged and the other masts fore-and-aft-rigged. Large numbers of barks were employed in carrying wheat from Australia to England before World War I; and in 1926 the bark Beatrice sailed from Fremantle, Western Australia, to London in 86 days.

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bark, in botany

bark, outer covering of the stem of woody plants, composed of waterproof cork cells protecting a layer of food-conducting tissue—the phloem or inner bark (also called bast). As the woody stem increases in size (see cambium), the outer bark of inelastic dead cork cells gives way in patterns characteristic of the species: it may split to form grooves; shred, as in the cedar; or peel off, as in the sycamore or the shagbark hickory. A layer of reproductive cells called the cork cambium produces new cork cells to replace or reinforce the old. The cork of commerce is the carefully harvested outer bark of the cork oak (Quercus suber), a native of S Europe. The phloem (see stem) conducts sap downward from the leaves to be used for storage and to nourish other plant parts. "Girdling" a tree, i.e., cutting through the phloem tubes, results in starvation of the roots and, ultimately, death of the tree; trees are sometimes girdled by animals that eat bark. The fiber cells that strengthen and protect the phloem ducts are a source of such textile fibers as hemp, flax, and jute; various barks supply tannin, cork (see cork oak), dyes, flavorings (e.g., cinnamon), and drugs (e.g., quinine). The outer bark of the paper birch was used by Native Americans to make baskets and canoes.

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bark

In woody plants, tissues outside of the vascular cambium. The term is also used more popularly to refer to all tissues outside the wood. The inner soft bark is produced by the vascular cambium; it consists of secondary phloem (food-conducting) tissue whose innermost layer transports food from the leaves to the rest of the plant. The layered outer bark contains cork and old, dead phloem. The bark is usually thinner than the woody part of the stem or root.

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bark

1. a protective layer of dead corky cells on the outside of the stems of woody plants

2. an informal name for cinchona

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bark [bärk]

(botany)

The tissues external to the cambium in a stem or root.

(metallurgy)

The decarburized layer formed beneath the scale on the surface of steel heated in air.

(naval architecture)

A three-masted sailing ship whose foremast and mainmast are square-rigged and whose mizzenmast is fore-and-aft-rigged.