KEY TO THE SPECIES

1Basal basiscopic lobes of basal pinnae shorter than those next to them
1'Basal basiscopic lobes of basal pinnae elongate, longer than those next to them.
2Stalks of basal pinnae c. 10 mm long
2'Stalks of basal pinnae much shorter, other pinnae mostly sessile
3Pinna-lobes broad and obtuse; costae bearing stiff short hairs at least near their bases
3'Pinna-lobes acute, costae quite glabrous
4Pinnae mostly short-stalked, their basal acroscopic lobes not or little overlapping the rachis; sinuses between pinna-lobes 2-3 mm wide
4'Pinnae (except the basal ones) quite sessile, their basal acroscopic lobes overlapping the rachis; sinuses between pinna-lobes very narrow
5Basal basiscopic lobes of basal pinnae distinctly longer than the next lobes; pinna-lobes slightly toothed distally; basal acroscopic veins in larger pinnae twice forked
5'Basal basiscopic lobes of basal pinnae little longer than the next lobes; the pinna-lobes strongly crenate-serrate almost throughout; basal acroscopic veins in larger ones once forked