Acronyms and Definitions
Cortex: outer layer of tissue immediately below the epidermis of a stem, consisting of various layers of thin- and thick-walled cells whose thicknesses increase from the outer to the inner layers
Culm: the hollow stem of a grass
Cutinize: to impregnate a cell with cutin, a waxy, water-repellent substance that provides a barrier and protects plant surfaces from water loss and microbial attack
Epidermis: the outermost, wax-coated layer of the cortex, consisting of axially elongated cells, shorter cork (dead) cells, stomata (pores), and silica cells, which contain a high amount of silica (silicon dioxide) strengthening the epidermal layer
Fiber cells: greatly elongated cells whose long, tapering ends interlock and provide maximum support to a plant. They usually occur in strands or bundles; colloquially, the totality of a bundle or strand is called fiber
Parenchyma: thin-walled cells that form the ground tissue and make up the bulk of most nonwoody structures. Parenchyma cell walls can be lignified
Pith ring: heavily thickened and lignified parenchyma cells that form the inner surface of the culm wall. A transition from extremely thickened parenchyma to true sclereids is observed in some species
Sclerenchyma: two types of thick-walled cells—fibers and sclereids (short cells with thick walls that fill nearly all the cell's volume)—that form the stiffening tissue
Sclerification: similar to lignification, the stiffening of cell walls by lignin deposition in cell walls
Vascular bundle: a strand of conducting vessels, sieve tubes, and fibers
Wax coating: prevents culm's loss and uptake of water