2 Dryopteris Athyrium and Polystichum
Three groups of ferns (genera), commonly found in British gardens have fronds of the bipinate type. That is to say the fronds are divided into side branches, which themselves have leaves down their edges. If the small leaves (pinnules), are roughly symmetrical in outline, as in 3 and 4 below, then you will have either Dryopteris or Athyrium. However if the leaves have “thumbs” on one edge,but only one edge, as in 1 and 2 (circled), then you have a Polystichum type.

