Photosynthesis (Net CO2 Exchange Rate) References
Cirsium arvense (L.) Scop. [Canadian Thistle]
Ziska, L.H. 2002. Influence of rising atmospheric CO2 since 1900 on early growth and photosynthetic response of a noxious invasive weed, Canada thistle (Cirsium arvense). Functional Plant Biology 29: 1387-1392.