STUDIES ON THE OPTIMUM CONDITIONS OF EXTRACTION OF SILICON SPECIES FROM PLANTS WITH WATER – II. Carduus acanthoides¹

Abstract

The silicon level has been determined in various organs of Carduus acanthoides L., Cirsium arvense (L.) Scop, and Cirsium palustre (L.) Scop. (Family Compositae). Of the plants studied, C. acanthoides turned out to be richest in silicon. Accordingly, optimum conditions have been established for the extraction of molybdate-reactive silicon species from its leaves using both dry and fresh material. The balance of silicon has been made, as well, and a relationship has been derived for the quantitative characterisation of the extraction. It is concluded that C. acanthoides may provide a cheap and easily accessible source of assimilable silicon.