Lepidium banksii, commonly known as Coastal Peppercress, is a species of flowering plant in the family Brassicaceae. This herbaceous perennial is endemic to the Chatham Islands of New Zealand, where it plays a role in its native coastal ecosystems. Its significance lies in its unique adaptation to harsh maritime environments and its contribution to the biodiversity of the region. The Coastal Peppercress typically presents as a low-growing, spreading plant. It forms dense mats or cushions, rarely exceeding 30 centimeters in height but often spreading wider. The leaves are a distinguishing feature, being pinnately divided or lobed, with a somewhat fleshy texture, an adaptation to its saline habitat. The leaf margins can be entire or toothed. During its flowering period, Lepidium banksii produces small, inconspicuous flowers. These flowers are typically white or pale pink, borne in terminal racemes. Each flower possesses four petals and a characteristic cruciform arrangement, typical of the Brassicaceae family. Following flowering, the plant develops small, ovate to oblong silicles, which are characteristic flattened seed pods of the genus Lepidium. These fruits contain small seeds. Lepidium banksii is exclusively found in the Chatham Islands, an archipelago east of New Zealand. It thrives in exposed coastal environments, colonizing sand dunes, rocky shores, and coastal cliffs. Its natural habitat is characterized by salt spray, strong winds, and sandy or gravelly soils. While not widely cultivated, its resilience to coastal conditions suggests potential for use in ecological restoration projects in similar environments. Cultivation requirements would likely include well-drained soil, full sun, and tolerance to saline conditions. The ecological importance of Lepidium banksii is primarily as a pioneer species in coastal colonisation, helping to stabilise sand dunes and providing habitat for small invertebrates. Its adaptations to the challenging coastal environment, such as its succulent leaves and low growth habit, allow it to survive where many other plants cannot. These adaptations are crucial for its survival in the dynamic and often nutrient-poor conditions of its native range. While not known for significant ornamental, agricultural, or medicinal uses, its role in its native ecosystem is scientifically recognized. Interesting facts about Lepidium banksii include its ability to tolerate high levels of salt, a common challenge for plants growing near the sea. Its presence is an indicator of healthy coastal plant communities in the Chatham Islands.