Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 75. (Budapest 1983)
Kováts, D.: Distribution of internode lengths of two Lithospermum species (Boraginaceae)
lengths is characteristic for every branch of Lithospermum arvense L. and it is different from L. purpureo-coeruleum L. Naturally the conclusions drawn in this work still require more measurements to reach definitive statements, but the observations made so far suggest that they are valid. Summary — According to the observations made so far, most of the specimens of Lithospermum purpureo-coeruleum L. have few shoots, in the majority of cases one specimen has one stoloniferous and one flowering shoot. The lengths of internodes of Lithospermum purpureo-coeruleum L. are usually very fluctuating. They show an S curve with two maxima when depicted graphically. The internodes increase in length from below to upwards, reaching smaller maximum mostly at the lower part of the shoots after follow a regression in lengths, and in the upper half of the shoot reach their real maximum in length. This maximum continues through several internodes. This S curve is especially characteristic for the internode lengths of the relative main axes and not so much for the branches of the axes. According to the observation made so far, apparently the lengths of internodes of stoloniferous shoots (longer shoots) of Lithospermum purpureo-coeruleum L. change on several occasions, but between limited boundaries, after 1-3 or 4 internodes after each other, the changes are from elongation to shortening and vice versa, while in the short shoots including the flowering shoots too. these changes frequently take place after 4-7 internodes. Comparing the flowering shoots of Lithospermum purpureo-coeruleum L. and L. arvense L., it may immediately be seen that the branches of L. arvense L. show greater diversity than the branches of L. purpureo-coeruleum L. — The internode lengths of flowering shoots were taken into consideration. It was found in L. arvense L. that the longest internode was the first branchy internode after the point of branches and it seems to be characteristic for all branches of L. arvense L. In L. purpureocoeruleum L. the longest internode is the last internode of the relative main axis before branches. This difference between the two species seems to be constant. This divergence may be explained by the difference in the growth rhythm between the two Lithospermum species. The growth rhythm of plants is naturally under the influence of exterior factors too. The study material originated from three different places (and from herbarium too) and they were collected over two years, thereby ensuring that this distribution of internode lengths should be due to mostly the specific growth rhythm of these two species. This rhythm is effective partly independently of exterior factors. — The internode lengths of the one-year old and two-years old flowering shoots and the first, second, and third branches of L. arvense L. have greater diversity (curves with 1-3 maxima) than the internode lengths of the flowering shoots of L. purpureo-coeruleum L. Naturally, the above verifications and conclusions are provisional and still require further measurements to make them a definitive statements, however, the general course of the graphs appear to be well founded and valid. Acknowledgement — I am most thankful to Miss J. ESZTERGÁLYOS for the preparation of the figures. References BERTHOLD. G. (1904): Untersuchungen zur Physiologie der Pflanzlichen Organisation. — Leipzig,. II., pp. 257. GRISEBACH. A. (1843): Beobachtung über das Wachsthum der Vegetationsorgane in Bezug auf Systematik. — Arch. f. Naturg., 1: 267-292. GROOM, P. (1908): Longitudinal Symmetry in Phanerogamia. — Phil. Trans. Roy. Soc. London. 200: 57 (in: TROLL. W., 1937: Vergleichende Morphologie der höheren Pflanzen, Berlin. I., p. 181188). HEGEDŰS, Á. (1974): Factors influencing the quantitative anatomical characters of the vine cane II. Structure of internodes at different levels of cane. — Acta agronom. hung., 23: 73-81. KOVÁTS. D. (1970): Quantitative xylotomic investigations on the xylem of our home ash trees. — Annls hist.-nat. Mus. nat. hung., 62: 153-173. KOVÁTS. D. (1973): Anatomical Investigations on the Vegetative System of Lithospermum purpureocoeruleum L. — Annsl. hist.-nat. Mus. nat. hung., 65: 109-125. KOVÁTS, D. (1976): Phleum studies I. Data on the taxonomy and morphology of Phleum Bertolonii DC. and Phleum pratense L. — Acta bot. hung., 22: 107-126. KOVÁTS, D. & STIEBER. J. (1972): Some observations on the dynamism of structural development in the stem-borne root of Lithospermum purpureo-coeruleum L. — Annls hist.-nat. Mus. nat. hung. y 64: 96-113.
