the large-leaved olearia of the Chatham Islands

Size
Height: 2-6 m
Lifespan
Perennial
Diet
Not applicable - autotrophic. Photosynthetic shrub or small tree. Obtains nutrients from thin, well-drained coastal soils.
Habitat
Chatham Islands. Grows in coastal forest, scrub, and exposed cliffs on the main Chatham Island and Pitt Island.
Range
Endemic to the Chatham Islands (Rēkohu), New Zealand. Found on the main Chatham Island and Pitt Island.
Endemism
Endemic
Main Threats
No significant threats due to island isolation. Climate change may affect coastal habitats. Restricted range increases vulnerability to localised disasters.
Population
Restricted to the Chatham Islands. Populations stable but range limited. Not threatened.
Conservation Status
data_deficient
Human Risk
harmless
Handling Note
native shrub, safe to handle
Conservation Note
Endemic tree daisy restricted to Chatham Islands; data insufficient for full threat classification.
Assessment
NZTCS Vascular Plants (2023)
Te Ao Māori
Macrolearia chathamica has no widely recognised Māori name. It grows on the Chatham Islands (Rēkohu). Home of the Moriori people. The plant is part of the unique biodiversity of the Chathams. A region of deep cultural and spiritual significance. Its survival depends on the protection of its island habitat.
Taxonomy shifted its genus. A tree daisy found only on the Chatham Islands. A close relative of M. semidentata but distinct in its leaves and flowers. Macrolearia chathamica is part of the unique flora of this remote archipelago. The leaves are large, leathery, with smooth margins (not toothed). The name chathamica refers to the Chatham Islands. The plant's only home. The flowers are white, daisy-like. Appearing in summer. Macrolearia chathamica was once known as Olearia chathamica. In 2022, the genus Macrolearia was created. To house the largest-leaved tree daisies. The Chatham Islands species were both moved into this new genus. On the Chathams, the tree daisy grows in coastal forest and on exposed cliffs. It tolerates wind and salt. It is a tough plant. Adapted to the harsh conditions of the remote Pacific. The Moriori people of the Chatham Islands knew this plant. They used the wood. They observed its growth. The plant was part of their traditional knowledge. Macrolearia chathamica is not threatened. The Chatham Islands are remote. The plant is safe there. But its range is small. A single fire or storm could affect a significant portion of the population. The two Chatham Islands Macrolearia species are similar but distinct. M. semidentata has toothed leaves. M. chathamica has smooth leaves. That is the main difference. It carries on.