About
Polystichum setiferum 'Dahlem' is a cultivated form of the soft shield fern, notable for its soft-textured, arching fronds with softly bristled pinnule tips. Fronds typically measure 30–120 cm long and remain fresh-looking through the season, the plant being evergreen or semi-evergreen. Stipes and many midribs carry cinnamon-brown scales that are visible close to the crown.
About the genus
Polystichum is a genus of ferns in the family Dryopteridaceae, subfamily Dryopteridoideae, according to the Pteridophyte Phylogeny Group classification of 2016. The genus has about 500 species and has a cosmopolitan distribution. The highest diversity is in eastern Asia, with about 208 species in China alone; the region from Mexico to Brazil has at least 100 additional species; Africa, North America, and Europe have much lower diversity.
Wikipedia contributors, "Polystichum", CC BY-SA 4.0 — Polystichum
In the garden
Polystichum setiferum 'Dahlem' belongs to the Dryopteridaceae and is a garden form of a fern native to southern and western Europe. The species is most abundant in Ireland, south‑west Britain, western France and north‑west Iberia, and is also found more locally as far north as northern Scotland and eastwards to the Crimea and Turkey; in the Mediterranean it usually occurs at higher altitudes. Plants typically produce four to ten drooping fronds on a mature specimen, each bipinnate once established. Give this cultivar conditions like those of a woodland floor: shelter from strong sun, a steady supply of moisture in summer, and a soil rich in humus. A position with shade or dappled light will protect the fronds from scorch; add leaf mould or well-rotted compost at planting and top with mulch to conserve moisture. Fronds are soft in texture and generally persist through the season, so remove only damaged or dead fronds to tidy the crown. Use Polystichum setiferum 'Dahlem' beneath trees, on shaded banks or at the back of a moist, shady border where its 30–120 cm fronds can arch downslope. On close inspection the cinnamon-brown scales on the stipes and the upward-pointing basal pinnules help confirm its identity.
