C. purpurascens was first described and published in Botanical Appendix to Captain Franklin's Narrative of a journey to the shores of the Polar Sea (Richardson) 731.
Loài này được R.Br. mô tả khoa học đầu tiên năm 1823. ^ C. purpurascens was first described and published in Botanical Appendix to Captain Franklin's Narrative of a journey to the shores of the Polar Sea (Richardson) 731.