Experimental evidence of abnormally deep penetration in some botanical targ
ets by low-energy ion beams is presented. The energy spectra of 818 keV He ions penetrating a 70 mum thick seed coat of maize, fruit peel of grape an
d of tomato all have a common feature. The leading edges of these broad spe
ctra indicate that some of the penetrating ions pass through the thick targ
ets easily and only lose a small ii-action of their initial incident energy
. Rutherford backscattering spectrometry and electron microprobe measuremen
ts are used to determine the argon concentration in multilayer samples of t
he seed coat of maize implanted by 200 keV Ar+ ions. The results show that
about 10% of the Ar+ ions can penetrate deeper than similar to 100 mum in t
hese samples.