Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 64. (Budapest 1972)

Kováts, D. ; Stieber, J.: Some observations on the dynamism of structural development in the stem-borne root of Lithospermum purpureo-coeruleum L.

Fig. 4. Young, multiarchal, schematically figured and longitudinally sectioned root (a) developing by elongation and secondary incrassation into old root (b). Certain bundles falling out, persisting subapical ones (usually 4) differentiating to form a compact xylem cylinder ; sclerotic pith already penetrating into upper levels. 1. primary xylem, 2. secondary xylem. rhizoderm. We found that prior to cortex separation the endodermal cells also divide by anticlinal walls and, after cortex separation, they too wear off, while periderm formation has already commenced below them in most of the cases (Plate V, Fig. 40, Plate VI.

, Figs. 41-44, Plate VIL, Fig. 50). Old roots have annual rings and are more or less ring-porous (Plate VIL, Figs. 51-52). In the central area, the primary bundles and the enclosed, sclerotized pith are usually discernible (Fig. 1. 1; Plate VI., Figs. 45, 46). The other type was observed in essentially longer and older roots. In our opinion this is a temporally and spatially more advanced stage of the development expounded above (Plate I., Figs. 5; Plate IL, Figs. 9-12, 15, 16; Plate IV., Fig. 29; Plate VII., Fig. 52). The polvarchal root presumably loses one after the other