Using string interpolation on the array is a bad idea - it won't neccessarily get you what you want. For example:

#!/usr/bin/perl -w
use strict; use warnings;

my @list = ('jumping turtle', 'frog', 'tadpole');
my $var = "turtle";

if ("@list" =~ /\b$var\b/) {
        print "yup\n";
}
[download]

happily reports a match even though just "turtle" doesn't appear in the array, it's a "jumping turtle". I would be reluctant to assume that such behavior is desirable...