Fig. 5.—Drawing showing tetrarch radial bundle
Fig. 5.—Drawing showing tetrarch radial bundle of root of Cimicifuga, magnified 110 diameters. The section was from a young root, in which the meditullium had undergone but little secondary change.
a, a parenchyma cell from cortex;
b, cell of endodermis;
d, outer end of xylem ray;
f,f, meristem forming between xylem ray and phloem.