In respect of exodermis and cortex structure, the root of Achlyphila distich a
(fig. 7) conforms to the pattern outlined above. The endodermis, which stains
bright orange-red (rather than pink, as in Abolboda) with safranin, possesses
U-shaped thickenings not exactly like any mentioned above. The endodermis
may be two cells wide in places, although this condition is rare and localized.
Two roots examined proved to be 11-arch and 13-arch respectively. No central
vessels are present. This is surprising in view of the large diameter of the
vascular core. Instead, one to several cells that have the wall-thickening and
staining characteristics of endodermis cells (figure 7, dark area in center of
vascular core) are present in this position. On account of their characteristics,
they probably should be regarded as endodermal cells, despite their location.
Phloem groups are extremely small and are scattered among the sclerified cells
of the vascular core. The pericyele is not interrupted. Significantly, there are
two or three layers of cells (as compared to fewer in Abolboda) between the
pericyele and the outermost vessels. Occlusion by tannin-like materials is characteristic
of many vessels.