Complex sentence: A number of these species (particularly "Helenium autumnale") have the common name sneezeweed, based on the former use of their dried leaves in making snuff, inhaled to cause sneezing that would supposedly rid the body of evil spirits.
Split into simpler sentences: A number of these species (particularly "Helenium autumnale") have the common name sneezeweed, based on the former use of their dried leaves in making snuff. It was inhaled to cause sneezing that would supposedly rid the body of evil spirits.