Page 64 – Trichomes


Page 64 – Trichomes



c. 1940



Fig. 57 . Trichomes. Transverse sections of the abaxial side of young leaves, i.e., center leaves of the leafy terminus of the stem (i.e., the "crown" or "top"), A and B, and a seedling leaf, C, to show early stages in the development of trichomes. A. First stage: expansion of the mother cell (tmc) of the trichome (formed from an epidermal cell). B. Third and fourth stages: the formation of the first peticlinal wall to cut off a proximal cell, i.e., the foot of the stalk (tfsc) and a distal cell, which divides periclinally to form a second stalk cell (tsc) and the initial cell of the trichome head (this stage is not shown). This latter cell divides anticlinally to form the first two daughter cells of the head (thdc) C, An early stage where the trichome head is considerably expanded and the stalk, consists of the foot cell (tfsc) and two other cells (tsc and tsc₁). ep, epidermal cells, each containing a silica body; gp, ground parenchyma cell; thc, central cells of the trichome head; thm, marginal cells of the same; tsb, small cells of the first hypodermal layer at the base of the trichome stalk. A and U, X400. C. X340.