Tongue fern (Pyrrosia lingua)
Pyrrosia lingua is a perennial evergreen fern that can grow epiphytically on tree trunks or rocks and can also form ground cover. It has a slender, creeping rhizome.
Overview
Pyrrosia lingua is a perennial evergreen fern that can grow epiphytically on tree trunks or rocks and can also form ground cover. It has a slender, creeping rhizome.
Origin and habitat
Pyrrosia lingua is native to Asia, with records covering China, Japan, Taiwan, the southern Korean Peninsula, and Indochina; more detailed sources also list Bhutan, Cambodia, eastern India, Laos, Myanmar, Nepal, Thailand, and Vietnam, and the Taiwan species list confirms it as native but not endemic to Taiwan. It can grow on rocks and on tree bark or trunks, occurs in drier forest environments, and may spread across the ground to form colonies; Japanese sources describe it as common in relatively dry forests.
Characteristics
A single source reports a mature height of about 30–40 cm; sources are few. It is generally reported to grow slowly and has a creeping rhizome. The simple leaves have distinct stalks and are thick, rather rigid, and leathery, with shapes described as lanceolate, elliptical, or ovate-elliptical; they may be yellow-green and have fine stellate hairs that give them a velvety appearance, while new leaves can appear white because of their conspicuous hairs. Sources describe the leaf surfaces differently, while fertile leaves are generally taller and narrower than sterile leaves, producing slight dimorphism.
Light
A single source reports that Pyrrosia lingua can be cultivated in low light. A specialist single source reports tolerance of bright indirect light.
Watering
Keep slightly dry.
Growing medium and mounting
A single source reports that container-grown plants can use a growing medium containing orchid bark.
Propagation
A specialist source reports that the spores become bright yellow later in the year. A specialist source reports that propagation by division is generally easier.
Common problems
A single source reports that Pyrrosia lingua is drought tolerant.
Identification
Pyrrosia lingua has a long, creeping, rather rigid rhizome with shield-shaped scales and thick, leathery simple leaves bearing stellate hairs. Sori occur on the undersides of the leaves and may densely cover them; a French source describes the sori as round to oblong and lacking indusia.
Photos
Sources
- Wikipedia (en): Pyrrosia lingua — CC BY-SA 4.0 · link
- Wikipedia (ja): ヒトツバ — CC BY-SA 4.0 · link
- Wikipedia (fr): Pyrrosia lingua — CC BY-SA 4.0 · link
- NC State Plant Toolbox: Pyrrosia lingua — copyright (facts only) · link
- TaiCOL 臺灣物種名錄: Pyrrosia lingua — CC BY 4.0 · link
- Hardy Fern Foundation: Pyrrosia lingua — © The Hardy Fern Foundation, facts only · link