Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 75. (Budapest 1983)

Kováts, D.: Distribution of internode lengths of two Lithospermum species (Boraginaceae)

ANNALES HISTORICO-NATURALES MUSEI NATIONALIS HUNGARICI Tomus 75. Budapest, 1983 p.61-70. Distribution of internode lengths of two Lithospermum species (Boraginaceae) by D. KOVÁTS, Budapest Abstract — Comparative measurements of internode lengths were taken from the soots of Lithospermum purpureo-coeruleum L. and L. arvense L. (mostly on living material). The distribution of internode lengths and its difference between the two species are discussed and illustrated by double graphical transfer. The longest internodes are immediately before branches in L. purpureo-coeruleum L. and in contrast the first branchy internodes are the longest in L. arvense L. In addition, this work deals with the difference of branches between the two species and the distribution of two kind of shoots of L. purpureo-coeruleum L. With 7 figures. Introduction — Some works, today already belonging to the classicals, have alreadydealt with the distribution of internode lengths, for example: MÜNTER (1841, 1843), GRISEBACH (1843), MOLL (1876), BERTHOLD (1904), GROOM (1908). TROLL (1937), but up-to-date publications containing mathematical analyses have also discussed this problem, e.g. HEGEDŰS (1974), SZUJKÓLACZA, SZŐCS & HORNOK (1975), KOVÁTS (1976), SZUJKÓ-LACZA & SEN (1977). STIEBER & KOVÁTS (1978) have demonstrated the rhythmic phenomena and their interference on the basis of internode growing of Lithospermum purpureo-coeruleum L. From the changes of internode lengths, conclusion can be drawn as to the specific growing rhythms of plants. It is well-known that at the separation of taxa, nearly exclusively only the differences of reproductive organs have been taken into consideration and scarcely or not at all have the characters of vegetative organs been regarded. Altough GRISEBACH (1843) pointed out as early as the last century that distribution of internode lengths is characteristic of a larger or smaller group of related plants. There are also differences between the internode lengths of the flowering shoots of Lithospermum purpureo-coeruleum L. and L. arvense L., the branches of the flowering shoots are also not the same; with these problems and the distribution of the two kind of shoots (stoloniferous shoots, without flowers and nutlets and flowering shoots, with flowers and nutlets) in Lithospermum purpureo-coeruleum L. are the subject of this work. Material and methods The study material was collected between 1969 and 1970, some specimens of Lithospermum purpureo-coeruleum L. were grown continously in an experimental garden under identical conditions. Material of herbarium specimens were also measured, and plants grown from seeds from herbaria were measured as well. Most of the study material originated from three parts of the ,,Budai-hegység" (near to Budapest). They are from ,,Remete-hegy" (from lime stone, Orno-Quercetum), from ,,Csikihegyek" (from dolomite), and one part of the Lithospermum arvense L. material originated from the margin of a plough-land of ..Pesthidegkút". The measurements were taken from July to September, when the flowering period was over or when the nutlets were ripening, as by this time the growing of the shoots and internodes. respectively, were generally over as well. In a total of 142 cases the distribution of stoloniferous shoots (without flowers and nutlets) and flowering shoots (with flowers and nutlets) of Lithospermum purpureo-coeruleum L. were observed. Out of these, in 84 cases the combination of shoot numbers by specimens have also been taken into consideration. The changes of internode lengths from bases to apices were measured on 22 shoots of 8 specimens of Lithospermum purpureo-coeruleum L. and on 36 shoots of 17 specimens of Lithospermum arvense L. The lengths of internodes are represented by the common graphical methods. On the ordinate the lengths of internodes in mm, and on the abscissa the internode serial numbers from the bases to apices are given. In this case actually the internodes are put one after the other vertically. Only some graphs of the most characteristic shoots are presented here. Beside this kind of graphs-showing the real lengths measurements of the internodes — other kinds of graphs have also been prepared. These