Complex sentence: In 1980, a rare hexaploid form of "Hordeum brachyantherum" was discovered in California within the populations of diploid and tetraploid "Hordeum brachyantherum".
Split into simpler sentences: In 1980, a rare hexaploid form of "Hordeum brachyantherum" was discovered in California. It was found within the populations of diploid and tetraploid "Hordeum brachyantherum".