Chinese ladder brake fern
Native to: Old world tropics and subtropics
Little is known about the movement of this plant out of its native range and into new areas, but it has been present in the Caribbean since the late 1800s and on continental America since the early 1900s. The earliest vouchered specimen for Florida is dated from 1927. Interestingly, Pteris vittata is a hyperaccumulator of arsenic and has been praised for its potential to remediate contaminated soils. Brake fern bears a close resemblance to swamp fern, Blechnum serrulatum. Swamp and brake ferns can be distinguished by the spore arrangement on the fronds. In brake fern, spores form lines along the edge of each pinna, whereas the spores of swamp fern form lines along the midrib of each pinna.
Habit: herbaceous fern.
Fronds: dark green in color and only once divided, growing generally < 12 inches in a sunny site but > 20 inches in shade.
Spores: spores form lines along the edge of each pinna.
Distribution in Florida: throughout.
Spreads via microscopic spores on wind, wildlife, and people, it prefers calcareous substrate and has been noted to grow in disturbed sites, pinelands in South Florida, and on buildings and structures in urban areas. While it has been observed to have increasing populations in Florida, its ecosystem impacts are unclear.
Spore production occurs year-round in Florida, making decontamination of equipment, clothing, and gear critical after working in infested areas.
Maintaining a healthy ecosystem with good species diversity will help to deter infestation.
Mowing or pulling the fronds, can reduce spore production and reduce fern populations. Rouging small, isolated patches may also be cost-effective.
There has been very little work performed on chemical control of brake fern. Ferns can be very difficult to control, and regrowth often occurs from the underground rhizoids. A 2 to 3% solution of glyphosate (Roundup, etc.) will probably be the most effective treatment, although triclopyr may also provide control (Garlon 4 at 0.5 to 2% solution plus surfactant at 0.25%).