Zealandia pustulata is a fern species found in New Zealand and eastern Australia, commonly known as Kangaroo Fern or Hound’s Tongue. Its scientific name reflects its primary geographic origin and the blister-like appearance of its reproductive structures. Recently reclassified from the genus Microsorum, this species is a component of the Australasian flora.
Characteristics and Identification
Zealandia pustulata is an epiphytic or rupestral fern, growing on other plants or rocks via its creeping rhizomes. These long, fleshy rhizomes range in color from yellow-green to golden brown. Their growing tips are covered in brown-black scales that shed, leaving distinctive scars.
The fronds are leathery and bright glossy green on their upper surface, with a paler underside. Their shape varies from undivided elliptic forms in young plants to pinnate outlines in mature specimens.
A distinguishing feature of Zealandia pustulata is its sori, prominent, round clusters of spore-producing structures. These are deeply impressed into the underside of the frond, creating a noticeable bulge on the upper surface, which gave the fern its specific name, “pustulata.”
Habitat and Distribution
Zealandia pustulata is native to New Zealand and eastern Australia. This fern thrives in a range of environments from coastal to montane areas.
It commonly grows on the ground, rocks, or tree trunks and branches. While found in moist, shaded sites, it is drought-tolerant, preferring more open and drier habitats. It occupies various strata within forested areas.
The fern is often found in wet sclerophyll forests, rainforests, and more open subalpine environments. It prefers partial to full shade.
Ecological Significance
As an epiphyte and lithophyte, Zealandia pustulata contributes to the biological diversity of host trees and rock faces, providing habitat and microclimates. It also influences local humidity and substrate stability.
The fern pioneers new growth on disturbed sites or exposed surfaces. By colonizing these areas, it contributes to the accumulation of organic matter and the initial stages of soil formation, helping create more favorable conditions for other plant species.
Its drought tolerance allows it to persist in challenging conditions, maintaining vegetation cover and contributing to ecosystem resilience.
Conservation and Threats
Currently, Zealandia pustulata is classified as “Not Threatened” in New Zealand, indicating a stable population within its native range. Despite its stable status, general threats to New Zealand’s native flora, such as habitat loss and invasive species, could affect local populations. Climate change, leading to altered rainfall patterns or extreme weather events, might also pose a long-term risk. However, its drought tolerance offers some resilience against drier conditions.
Zealandia pustulata is easy to cultivate, making it suitable for gardens or terrariums. This can indirectly contribute to its preservation by raising public awareness of native ferns.