What common characteristic does the Pulmonaria and Bursera genuses have?
Pulmonaria: Pulmonaria (lungwort) is a genus of flowering plants in the family Boraginaceae, native to Europe and western Asia, with one species ("P. mollissima") east to central Asia. Bursera: Bursera, named after the Danish botanist Joachim Burser (1583-1639), is a genus with about 100 described species of flowering shrubs and trees varying in size up to 25 m high.
i don't know