from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A supportive tissue of plants, consisting of elongated living cells with unevenly thickened walls.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A supporting ground tissue just under the surface of various leaf structures formed before vascular differentiation.
from the GNU version of the Collaborative International Dictionary of English
- n. A tissue of vegetable cells which are thickend at the angles and (usually) elongated.
from The Century Dictionary and Cyclopedia
- n. In botany, a layer of modified parenchyma immediately beneath the epidermis, having the cells thickened at the angles by a pad-like mass which is capable of swelling greatly in water. It is found in the young stems, petioles, and leaf-veins of many dicotyledonous plants.
Both are embedded in a dense parenchyma tissue (= ground tissue), called pith, with usually some structural collenchyma tissue present.
They give flexible support to immature regions of plants (e.g., a celery stalk is mostly collenchyma).
Ground tissue forms the bulk of the plant; it contains parenchyma, collenchyma and sclerenchyma cells.
Slide 12: F F F F ก 40x xylem parenchyma epidermis collenchyma chlorenchyma