What is "sword fern"

n. any of several tropical ferns having more or less sword-shaped fronds including one from which the Boston fern developed

Sword fern is a common name for several ferns and may refer to:

• Nephrolepis, a tropical genus of ferns, especially:
  • Nephrolepis exaltata, commonly cultivated as a houseplant, including the Boston fern
• Polystichum, a cosmopolitan genus of ferns, especially:
  • Polystichum munitum, native to western North America