Inland peppercress one of our rarest plants

Inland peppercress (Lepidum solandri) is a herb plant that is so rare there are less than 1000 plants known in the wild.

It grows in tussock grassland and bare hillsides in Canterbury and Otago – in the project area these are often sites that are threatened by weeds and browsing animals.

It is an inland species of cress in the same genus of the equally rare coastal cress, Cook’s scurvy grass (Lepidium oleraceum), which Cook “collected by the boat load” to prevent scurvy in ship crews visiting New Zealand during the late 1700s and early 1800.

Lepidium means scale shaped and refers to the pods of tiny scented flowers which turn into small capsules on female plants. The flowers appear from September to January and can be green or white. Solandri refers to Swedish naturalist Daniel Carlsson Solander.

In addition to habitat loss, another reason Lepidium solandri is so rare and threatened is that it’s highly susceptible to a ‘fungus’ or rust infection (Albugo) carried by the white butterfly. It’s conservation status is Threatened – Nationally Critical. Over time the project’s rabbit and invasive weed control will help the survival of Lepidium solandri.

Photos Robyn Janes