We evaluated the growth and development of the medicinal species Pothomorphe umbellata (L.) Miq. under different shade levels (full sun and 30, 50, and 70 % shade, marked as I 100 , I 70 , I 50 , and I 30 , respectively) and their effects on gas exchange and activities of antioxidant enzymes. Photosynthetically active radiation varied from 1 254 μmol m −2 s −1 at I 100 to 285 μmol m −2 s −1 at I 30 . Stomatal conductance, net photosynthetic rate, and relative chlorophyll (Chl) content were maximal in I 70 plants. Plants grown under I 100 produced leaves with lower Chl content and signs of chlorosis and necrosis. These symptoms indicated Chl degradation induced by the generation of reactive oxygen species. Stress related antioxidant enzyme activities (Mn-SOD, Fe-SOD, and Cu/Zn-SOD) were highest in I 100 plants, whereas catalase activity was the lowest. Hence P. umbellata is a shade species (sciophyte), a feature that should be considered in reforestation programs or in field plantings for production of medicinal constituents.