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1 Petiole and rachis lacking scales, but with acicular hairs and minute comblike hairs; veins (1-) 2-4-forked; sori surrounded by an oblong patch of erect hairs; segments at base of blade gradually reduced to auricles; [usually terrestrial]
..2 Veins (1-) 2-forked; scales of the rachis and petiole hastate-cordate, flat; spores 32 per sporangium, mostly spherical; [usually on rocks]
..2 Veins 1-forked; scales of the rachis and petiole cordate, appearing inflated; spores 64 per sporangium, mostly reniform; [usually epiphytic]