oak fern
释义（英文）
名词 Noun
- A fern of genus Gymnocarpium (syn. Thelypteris) which grows on trees, especially Gymnocarpium dryopteris.
- A bat's wing fern (Histiopteris incisa)
- Synonym of common polypody (Polypodium vulgare), a fern formerly thought to have medicinal properties when found growing on an oak.