1. Yellow-green fern of rocky areas of northern hemisphere
   - northern oak fern, Gymnocarpium robertianum

Derived forms: limestone ferns

Type of: fern

• gas furnace
• gas gage
• gas gangrene
• gas gauge
• gas giant
• gas gun
• gas guzzler
• gas heat
• gas heater
• gas helmet
• gas holder
• gas jet
• gas lamp
• gas line
• gas main
• gas maser
• gas meter
• gas mileage
• gas oil
• gas oven
• gas pedal
• gas phlegmon
• gas plant
• gas pressure
• gas pump