Estimation of the photosynthetic surface fronds area of the Dryopteris carthusiana (Dryopteridaceae)

The area of the photosynthetic surface of Dryopteris carthusiana fronds was estimated using the ImageJ program. The area of the photosynthetic surface of one frond of the narrow buckler-fern in the coniferous forests of the Moscow region averaged about 380 cm², and, given the presence of 6-7 fronds in each adult, the area of the photosynthetic surface of one middle-aged sporophyte reaches 2660 cm2.