What type of category does Bletilla and Vernonia have in common?
Bletilla: Bletilla, common name urn orchid, is a temperate, terrestrial genus of orchids containing five currently recognized species distributed through China, Japan, Taiwan, south to Vietnam, Thailand and Myanmar. Vernonia: Vernonia is a genus of about 1000 species of forbs and shrubs in the family Asteraceae.
i don't know