CYSTOLITHS
Cystoliths consist of calcium carbonate deposited over and around a framework of cellulose.
FORMS OF CYSTOLITHS
The forms of cystoliths differ greatly in the different plants in which they occur.
In the rubber-plant leaf, the cystolith resembles a bunch of grapes and is stalked; in ruellia root (Plate 87, Fig. 1) the cystoliths vary from nearly circular to narrowly cylindrical, and no stalk is present; also the cystolith nearly fills the cell in which it occurs. In the hair of cannabis indica (Plate 88, Fig. 3), the cystolith varies in form according to the size and shape of the hair, but in all the hairs the cystolith appears to be attached to the upper curved part of the inner wall of the hair.
PLATE 85
Solitary Crystals
1. India senna (Cassia angustifolia, Vahl.).
2. Cascara sagrada bark (Rhamnus purshiana, D. C.).
3. Frangula bark (Rhamnus frangula, L.).
4. White pine bark (Pinus strobus, L.).
5. Tamarac bark (Larix laricina [Du Roi], Koch).
PLATE 86
Solitary Crystals