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.

Plaie II. Habit pictures. Fig. 9: Vegetative shoot, taken to roots during previous year, now appearing as a rhizome, developing vegetative and reproductive shoots as a distinct j)lant. Fig. 10: Vegetative shoot section, having emitted roots at several points during previous year, by the spring producing shoots according to points of rooting ; Fig. 11 : By early spring, rooted and hypogeally overwintered shoot apex producing shoots; Fig. 12: Old, probably several years old shoot apex (rhizome); — Cross-sections of vegetative shoots and rhizome. Fig. 13: Root protuberance, originating from medullary ray of young shoot apex, splitting and then breaking through shoot cortex ( X 20) ; Fig. 14: Young, still fascicular (collaterally open) shoot structure from levels of rooting ( X 90); Fig. 15: Cross-section of older, secondarily already much thickened rhizome; xylem a contiguous thick ring (x80); Fig. 16: Triangular cross-section of rhizome; secondarily incrassate strong, contiguous xylem ring with two root emissions ( X 20). Plate III. Fig. 17: Secondarily incrassate rhizome cross-section, and longitudinal section of emitted root; median part of root with longitudinal section of sclerotic (simply pitted) pith parenchymatous cells, followed towards cambium by xylem elements ( x 120) ; — Cross-sections of young roots. Fig. IS: Oval central cylinder, with some xylem bundles at base of root-hairy zone (Xl45); Fig. I !): Some xylem bundles with a more developed phloem fascicle in tangential position ( X 260); Fig. 20: Developed phloem bundles with more xylem fascicles, medially with pith parenchyma (Xl20); Fig. 21: Approximately circular root, with an oval central cylinder, in the root-hairy zone ( X 95) ; Fig. 22 : Oval central cylinder with 8 xylem bundles, medially pith parenchyma ( X 160); Fig. 23: Near shoot already 9 xylem bundles present, 1-2 in tangential position ( X 95); Fig. 24: Still more bundles in tangential position, hence ring apparently contiguous in certain sections; waved cambium formed in a ring ( X 120). Plate IV. Cross-sections of young roots. Fig. 25: Multiseriate waved cambium already beginning introduction of secondary xylem among primary bundles ( X2(50); Fig. 26: By the integration of secondary xylem, the contiguous xylem ring forms in ever longer sections (xl55); Fig. 27: Multiseriate xylem ring enclosing parenchymatous ring ( x 120): Fig. 28: Differentiation of bundle al levels adjacent lo shoot two-directional ; metaxylem vessels medially | 1030).- Cross-sections of older root near apex. Fig. 29: Still undifferentiated triarchal structure: pericambium biseriate above xylem bundles, endoderm Caspary-punctate (-striate), cross-section of central cylinder circular ( 20(1); Fig. 30: Undifferentiated, tetrarchal structure in root-hairy zone (xl20); Fig. 31: Tetrarchal structure before differentiation: pericambium 2-3-seriate above xylem bundles, endoderm Caspary-punctate (-striate); cross-section of central cylinder circular ('260); Fig. 32: Phase f of tetrarchal differentiation (Fig. 3); waved cambium under development ( x 155). Plate V. Cross-sections of older root near apex. Fig. 33: Phase g of tetrarchal differentiation (Fig. 3); waved cambium under development ( x 260); Fig. 34: Phase e of tetrarchal differentiation (Fig. 3); waved cambium formed into a ring ( X 200) ; Fig. 35: Tetrarchal procambium already differentiated, waved cambium closed into a ring ( x 155); Fig. 36: By the integration of secondary xylem, formation of compact xylem cylinder begins; a wide cambial zone already formed, number of phloem bundles increased ( X 115);—Cross-sections of older roots. Fig. 37: Xylem further strengthening, its cross-section still oval; precambial zone and endodermal cells dividing anticlinally; root covered by exoderm ( X 65); Fig. 38: Oval xylem, mainly from secondary vessels; number of phloem bundles increased; cells of pericambial zone divided anticlinally ( X 155); Fig. 39: Perforation of several vessels sieve-like in xylem cylinder ( x 120); Fig. 40: Xylem cylinder rounded in upper levels; cells of pericambial zone and endoderm divided also anticlinally ( X 40).