Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 63. (Budapest 1971)

Kováts, D.: Some histological observations on Lihospermum purpureo-coeruleum L. seedlings

Plate II Radicula : Fig. 1 = Cross section of young, diarchic radicula, with large, isodiametric parenchymatous cells of cortex (outer border the rhizoderm), and radicular hairs ( x 100) ; Fig. 2 = Stele centrally with still undifferentiated procambial fascicle. One xylem fascicle radial, the other one tangential. Pericambium biseriate over both xylem fascicles. Inner cellular row of cortex Cacpari-punctate endoderm (cross section, x450); Fig. 3 = Parenchymatous pith cells within phloem fascicles dividing by tangential walls, thus producing parL of the waved cambium in this section (cross section, x480); Fig. 4 — Procambium not wholly differentiated yet; waved cambium formed also outside of xylem fascicles and thus closed early into a ring (cross section, X 200). Plate III Radicula : Fig. 1 = Wall of protoxylem vessels spirally, those of metaxylem bordered-pittedly thickened. Cells of cortical parenchyma elongated (longitudinal section, x250); Fig. 2 = Tracheal row becoming multiseriate in the cotyledonary plane by the secondary vessels produced by the waved cambium (cross section, Xl90); Fig. 3 = Waved cambium emitting numerous secondary vessels in the transverse plane, perpendicularly to proto- and metaxylem rows of vessels; xylem thus becoming cruciform (cross section, x 150); Fig. 4 = Compact xylem cylinder evolved; tracheal rows radially situated (cross section, x 90). Plate IV Radicula and hypocotyl: Fig. 1 = Cells of pericambial zone of older seedling radicula dividing by radial walls. Endoderm becoming secondary (cross section, x390); Hypocotyl: Fig. 2 = Tracheal row dividing and widening, turning from radial into tangential position in two weeks old seedling. Caspari-punctate epiderm also a starchy sheath (cross section, x320); Fig. 3 = Near insertional points of cotyledons, the two collateral open fascicles arranging into the cotyledonary plane to enter the cotyledons. Concomitantly, a collateral open fascicle each entering in the transverse plane; these latter continuing in the epicotyl (cross section, xl60); Fig. 4 = Cotyledons separating, both with two collateral open fascicles: epicotyl in middle, with two collateral open fascicles, cambium already a continuous ring. A meristematic group of cells axillary of each cotyledon (cross section, x 90). Plate V Hypocotyl and epicotyl : Fig. 1 = Older (one month old) hypocotyl with continuous xylem ring; a part of it, together with the corresponding cambial and phloem parts, entering the cotyledons. Pith parenchyma consisting of large, isodiametric cells in middle. Hypocotyl bordered by epidermal cells with hairs containing a cystolith (cross section, Xl50); Fig. 2 = Hypocotyl with discontinuous phloem row, 4—5-seriate cambium and continuous xylem ring (cross section, x390); Fig. 3 = A continuous xylem ring also in epicotyl already present in one month old seedlings. Medially a pith parenchyma consisting of large, isodiametric cells. Epiderm forming cortical border with hairs containing large cystoliths (cross section, x60); Fig. 4 = Cross section of epicotyl tending more and more oval; two collateral open fascicles entering first leaves in transverse plane ( X 60). Plate VI Epicotyl : Fig. 1 = Leaves separating from epicotyl (cross section, x 60) ; Fig. 2 = Leaves separating from epicotyl, axillarily with shoot initiations, with two already differentiated fascicles (cross section, x 60) ; Fig. 3 = Xylem ring disrupting near shoot apex (cross section, xl50); Fig. 4 = Xylem ring separating into radial rows of 2 — 3 tracheae and solitary tracheae. Cambium 5 —6-seriate (cross section x390). Photographs by D. KOVÁTS.