About Polystichum proliferum (R.Br.) C.Presl
Polystichum proliferum (R.Br.) C.Presl is a terrestrial fern that grows up to 130 cm in height. Its rhizome and frond bases are covered in persistent, glossy brown scales with pale edges. Mature fronds are dark green, while young fronds are lighter and paler; fronds can reach up to 100 cm long and 30 cm wide. Spore clusters called sori grow in rows on either side of the frond midrib, and each sorus is covered by a large, umbrella-shaped protective structure called an indusium. This feature gives the species its common name, mother shield fern.
This fern is widespread and abundant from sea level up to 1300 m above sea level, and it occurs predominantly in the tablelands and ranges of New South Wales, Victoria, the Australian Capital Territory, and Tasmania. At higher elevations, it grows among boulders, while at lower altitudes it is found in wet forests. It typically favors gullies, creeks, and cooler, moister southern and eastern-facing slopes. Thanks to its hardy traits, including tolerance for salt-laden winds and poor soil quality, it can also grow in drier vegetation types such as coastal scrub and dry sclerophyll forest. It is often associated with gullies occupied by Dicksonia antarctica, growing higher up these gullies and further from watercourses than D. antarctica. The close association and similar appearance of these two species often leads novice plant collectors to misidentify Polystichum proliferum as Dicksonia antarctica.
Polystichum proliferum can reproduce both vegetatively via proliferous buds and sexually through spores. For vegetative reproduction, bulbils develop at the tips of larger fronds and grow into small new plants. As the bulbil gains weight, the supporting frond sags until the bulbil can take root in the soil below. This trait allows the species to colonize large areas through vegetative growth, and it often becomes the dominant ground cover after a disturbance. This characteristic also makes it a popular cultivated plant for home gardens.
