prosenchyma

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A type of plant tissue consisting of elongated cells with tapering ends, occurring in supporting and conducting tissue.

Century Dictionary and Cyclopedia

1. n. In botany, the fibrovascular system or tissue of plants; the cells and modified cells which constitute the framework of plants, as distinguished from parenchyma, or the cells which constitute the soft tissues of plants. See parenchyma. In most of the lower plants it is barely if at all developed, but in the higher plants it exists as a skeletou which brings all the parts into closer relation. The solid wood of trunks and the veins of leaves are familiar examples. As in parenchyma, the cells composing this tissue are very various in form, size, etc., and have been minutely classified, yet they may be reduced to a few comparatively simple types. These cells, which are normally of considerable length in proportion to the transverse diameter, are generally more or less sharply pointed, and are divided into typical wood-cells and woody fibers (including libriform cells and secondary wood-cells) and vasiform wood-cells or tracheids. The most important modification is that in which cells belonging to this system unite to form long rows in which the terminal partitions are nearly or quite obliterated, throwing the cavities into one, forming a duct. These ducts or vessels may be dotted, spirally marked, annular, reticulated, or trabecular. A modification in a different direction produces bast-cells, bast-fibers, or liber-fibers. See also wood-cell, libriform cells (under libriform), duct, 2 , bast, 2, liber, 1.

Wiktionary

1. n. botany The tissues formed of elongated cells, especially those with pointed or oblique extremities, such as the principal cells of ordinary wood.

GNU Webster's 1913

1. n. (Bot.) A general term applied to the tissues formed of elongated cells, especially those with pointed or oblique extremities, as the principal cells of ordinary wood.