Sclerenchymatous cells

The main components of inner bark are sieve elements, parenchyma cells, and sclerenchymatous cells. Sieve elements perform the function for transportation of liquids and nutrients. More specifically and according to their shape the sieve elements are divided into sieve cells and sieve tubes. The former types are present in gym nosperms, the latter in angiosperms. The sieve elements are arranged in longitudinal cell rows which are connected through sieve areas. The sieve cells are comparatively narrow with tapering ends, whereas the sieve tubes are thicker and cylindrical. After 1 -2 years, or after a longer time in the monocotyledons, the activity of the sieve elements ceases and they are replaced by new elements. 

Cortex, of many layers of cortical parenchyma cells with brown walls. The outer layers of cells of this region are thin-walled, while the extreme inner ones are lignified and form a sclerenchymatous ring which surrounds the... 

There is an obvious connection between crystal chemistry and natural products. Crystals appear in plant material (3,4)—calcium oxalate is extremely common potassium acid tartrate in outer perisperm cells of nutmeg hesperidin and diosmin in cells of many of the Rutaceae calcium carbonate in cells of Cannabinaceae silica in the cells of the sclerenchymatous layer of cardamom seeds. The crystallizing temperature of the solid complex between 1,8-cineoIe and o-cresol forms the basis for official assay of oil of eucalyptus (4). Also worth noting is the fact that alkaloids, particularly brucine, are widely used to resolve optically active acids by diastereoisomer fractional crystallization (5). 

---