Retrieved August 13, 2010.  C. purpurascens subsp. maltei was published in Publications in Botany, National Museum of Natural Sciences, Canada, no. 4: 5.
Truy cập ngày 13 tháng 8 năm 2010.  ^ C. purpurascens subsp. maltei was published in Publications in Botany, National Museum of Natural Sciences, Canada, no. 4: 5.