Carduus pycnocephalus L

Chicago citation style
Carduus pycnocephalus L. 13 Aug 1938. Retrieved from the Digital Public Library of America, http://collections.si.edu/search/results.htm?q=record_ID%3Anmnhbotany_12976960&repo=DPLA. (Accessed November 16, 2018.)
APA citation style
(13 Aug 1938) Carduus pycnocephalus L. Retrieved from the Digital Public Library of America, http://collections.si.edu/search/results.htm?q=record_ID%3Anmnhbotany_12976960&repo=DPLA
MLA citation style
Retrieved from the Digital Public Library of America <http://collections.si.edu/search/results.htm?q=record_ID%3Anmnhbotany_12976960&repo=DPLA>.
Note: These citations are programmatically generated and may be incomplete.