A Comparison of Lower and Higher Plants as Accumulators of Radioactive Fall-out

In an earlier paper (1) accumulation of radioactive fall-out by plants in the English Lalte District was related to the mineral content of the various species, with both mosses and angiosperms low in mineral ash showing nluch more radioactivity than plants of high mineral content in the same groups. The present study compares radioactivity of ash from lichens, mosses, and angiosperms, using some of the data previously employed, plus cou~l t s for three lichens made toward the end of the work already reported. The plants were collected in early 1958. Samples were dried a t 105 to 110" C and ashed a t bright-red heat. Aliquots of about 50 mg ash were fixed in planchets with "Celloidin" and tested within three days of collectio~l j for radioactivity, in a lead tower with CV 2139 counter tube (end-\vindom 1 weight 2.3 mg/cm2). A t least 1000 counts were recorded for each sample