This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
A very large genus, now including Cyrto-mium and Polystichum, and having representatives in the tropical and temperate regions. A. (Polystichum) aculeatum is a well-known species called the "Hard or Prickly Shield Fern". It has twice-pinnate stiffish fronds about 2 ft. long, and is quite hardy. A. angulare, the "Soft Shield Fern", is considered a variety of it, but is a very distinct plant; and there are almost innumerable varieties having the fronds beautifully crested, lobed, and tasselled, and much admired by hardy-Fern specialists.
A. (Polystichum) Lonchitis, another hardy species, known as the "Holly Fern", must not be confused with the greenhouse species A. (Cyrtomium) falcatum, also called "Holly Fern". It grows wild in the Scottish Highlands and has fronds 1-2 ft. long.