How do fern gametophytes obtain water and minerals?

Fern gametophytes, also known as prothallia, are typically small, green, and heart-shaped structures that develop in moist, shaded environments. Because they lack the complex vascular systems found in mature sporophytes, they obtain water and minerals primarily through direct absorption from their immediate surroundings.1234

Most fern gametophytes are anchored to surfaces such as moist soil, rocks, or tree bark by unicellular, rootlike structures called rhizoids. These rhizoids facilitate the uptake of water and necessary minerals directly from the substrate.4

While the majority of fern gametophytes are photosynthetic and produce their own food, there are exceptions. For instance, in certain genera such as Ophioglossum and Botrychium, the gametophytes are subterranean and lack chlorophyll. These non-photosynthetic gametophytes rely on a symbiotic relationship with associated fungi, which provide the necessary nutrients through their filamentous structures (hyphae).4