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

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

1. Table. Distribution of stoloniferous and flowering shots per individual number of specimens number of stoloniferous shoots number of flowering shoots 26 I 1 9 2 1 8 I 2 7 0 2 7 3 1 5 2 2 4 3 2 3 2 3 2 I 3 2 4 1 1 1 0 1 2 0 I 3 0 1 0 3 1 4 0 I 4 2 1 2 4 1 3 4 1 2 • 5 I 3 5 1 5 4 the internode lengths of Lithospermum purpureo-coeruleum L. It means that most of the internodes of the shoots increase in lengths from below to upwards (the first „smaller maximum") after this a regression follows, than the lengths of internodes reach their maximum (the second „real maximum") generally at the beginning or at the middle of the second part of the shoot length (Fig. 2). This "real" maximum of internode length is usually continuous through several internodes, changing in lengths, namely the longest internodes change with shorter internodes through the second upper parts of shoots. This fluctuation of internode length is especially characteristic for the stoloniferous shoots of Lithospermum purpuereo-coeruleum L., collected at „Remete-hegy" and grown in an experimental garden (Fig. 2). These three are the longest shoots among the measured materials. Other plants, forest litter and dead grasses did not hinder the lengthening of the shoots and the radication under the circumstances of the experimental garden. Curve S, mentioned above, is rather characteristic only for the relative main axes of the specimens and it is not so characteristic for the shoots branching off the main axes. It is also not so characteristic for the internode lengths of flowering shoots of Lithospermum purpureo-coeruleum L. (Fig. 6). Great changes in internode lengths may be seen on the second part of the graph (Fig. 2). With this method one may get a deeper inside view of the growth rhythm of plants and in many cases of the regular recurrence of growth „pulsing". It is interesting that these fluctuations and rhythmical changes of growth seem to be more compensated in the long shoots (mostly at stoloniferous shoots) than at the shorter (mostly at flowering shoots). In the long shoots, after relatively few (1—4) internodes (following each other), the extension or reduction of length change to the opposite, namely after 1—4 internodes which are elongating, 1—4 internodes follow which are shortening and vice versa. The situation is not the same in the short shoots (mostly the flowering shoots), here sometimes 4—7 internodes follow each other before the changing from elongation to shortening of length and vice versa takes place. 5 Természettudományi Múzeum Évkönyve 1983