Abstract
Silica deposits in young plants of Digitaria sanguinalis (L.) Scop., cultured in nutrient solutions containing two levels of SiO2, were investigated by techniques including phase contrast microscopy and the electronprobe microanalyser. Field-grown specimens were included in the study for comparison. Progressive silicification over 20 days of early leaf ontogeny is described and compared to that for other species. Si microassay results for culms and roots are combined with loeaf data in order to interpret overall deposition strategy for the species. Comparisons between soil and water-cultured speciments suggest that the extensive mesophyll silicification occurring in the latter is atypical, and may influence growth. An attempt is made to account for this latter silicification in terms of Kranz leaf anatomy.