Shoestring Fern (Vittaria lineata) is an epiphyte with fronds (leaves) that resemble green spaghetti or green shoelaces.

As an epiphyte, a shoestring fern usually grows on a boot jack of sabal palm. It is not parasitic; instead, it gets its moisture and nutrients from the air, rain, and debris that accumulates in the boot jack. After a rain, its color becomes bright green. During a drier period, it becomes brown.

Shoestring fern stems are short and creeping, branched, and very scaly. The scales are brown.

As with other ferns, shoestring fern has alternating generations. One generation reproduces asexually, while the next reproduces sexually. The photograph below at left shows both generations. The generation that looks like shoestring is the asexual stage, the sporophyte. This stage produces spores.

 

At right is a close-up of the bottom of a sporophyte frond. The yellow particles in the grooves are spores. Spores are carried away in the wind, land on substrate, and develop into sexual gametophytes.

 

The photograph at left shows a close-up of gametophytes. They are small, branched, and form a cover on moist logs and sabal palm tree trunks. Gametophytes reproduce, creating offspring that are sporophytes. Note the size difference between sporophytes and gametophytes in the photograph above.

Vittaria lineata is a threatened species in Florida. The definition of a "threatened species" is a species likely to become endangered.

Historically, shoestring fern has been used medicinally by indigenous Native Americans. A root mixture of resurrection fern (Polypodium incanum) and shoestring fern was made into a bath by both the Florida Seminoles and Miccosukee tribes to treat chronic conditions, including insanity.