Stems long-creeping; hairs many celled, rigid to lax. Leaves usually separated several centimeters, of apparently indeterminate growth; pinnae opposite, in 1--several pairs, each pinna 1--many times forked, equal, each fork bearing arrested apex (bud) covered with tuft of hairs (all other axes glabrous) and pair of stipulelike appendages. Penultimate segments pectinate, in ± equal pairs, usually ascending. Veins 2--4-forked. Sori with 6--15 or more sporangia, not paraphysate. Spores trilete.