This is an extremely unusual Ben Zuckerman dress that I believe dates from the late 1960's. The styling is somewhat conservative and covered up, as the length of the dress probably falls to knee length but the pattern is 'wild'.
Of course the tailoring is top notch and the dress is fully lined in green silk. This would have been a perfect dress for an older lady who wanted to wear the youthful styles of the late 1960'.
Photos courtesy of Barbara's Panache.