Alberto VojtÃÂch Frià(, 8 September 1882 Prague – 4 December 1944 Prague) was a Czechoslovak botanist, ethnographer, writer and explorer. He undertook 8 voyages to America, discovered, described and catalogued many species of cactus. South American Indians called him KaraàPukú (engl. Long Man); in Europe he became known as Cactus Hunter.