Ladder Brake - Chinese Brake
Pteris vittata - Linnaeus
Pteridaceae Family

 

This elegant fern has attractive shiny leaves and is easy to distinguish from other ferns by its relatively large size, the simple-pinnate structure of its leaves, and its long slender leaflets with smooth margins. It is indigenous to Asia, tropical Africa and Australia. Its preferred habitat is to grow on brick walls, or areas often associated with limestone. It may be seen growing on concrete structures and cracks.

Although it grows readily in the wild, the plant is sometimes cultivated in gardens for its attractive appearance, or used in pollution control schemes, as it is known to be a hyper-accumulator plant of arsenic. The plants have been shown to thrive under high arsenic conditions, this being a competitive advantage for the species. Therefore small patches in seemingly isolated areas may be an indicator of a high arsenic contamination in the soil

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 leaflet, whereas the spores of swamp fern form lines along the midrib. Fronds of brake fern are dark green in color and only once divided, growing generally to 12 inches in sunny sites but upward to 20 inches in shade. Fertile fronds bear sporangia (spore producing structures) on the underside of fronds.



Millions of spores are produced during the life cycle of a single fern, safeguarding the persistence of fern populations. Spore survival is low compared to the number of spores that are produced; however, this plant can out-compete native vegetation due to its invasive nature. The amount of spores produced can certainly provide a challenge for its control. Steps to prevent spore movement or formation are the key in controlling brake fern. Since the microscopic spores are easily transported via clothing, wind and possibly water, contamination is a constant threat. Control measures should be employed when the fern is not producing spores, which occurs year-round in this area.

Previous Page     Return to Index     Next Page