Fig.
10.4-3.
Transverse section of wild ginger (Asarum canadense in the Aristolochia
family, not a real ginger). The cells of this uniseriate trichome are slightly
collapsed, probably an artifact. Notice the alignment of the cells: this trichome developed by cell divisions in which
all new walls were perpendicular to the long axis of the trichome.
That orientation though is at right angles to the divisions that occurred as the
protoderm was developing into the epidermis. About nine trichome cells are
visible in just this micrograph, and probably each would have lengthened greatly
during maturation, creating a long trichome.