Jenny Harris, of Balclutha Primary School, asks :-
I came across a large patch of this plant in a shady place under a group of trees. What is it and is it useful?
Tim Curran, an ecologist at Lincoln University, responded.
I must confess that I didn’t know what it was either. I had to ask a colleague of mine, Dr Jon Sullivan, and he provided me with the answer. It is quite common for scientists to ask each other such questions as no one scientist will know everything. Jon and some of his colleagues have actually recently set up a new website (Nature Watch NZ: http://naturewatch.org.nz/) which allows anyone to upload photographs of plants and animals and get them identified by others (by checking the ‘ID Please’ box when you upload a photo). You and your class might be interested in this website.
Your plant is Miner’s Lettuce (scientific name: Claytonia perfoliata). This plant is not native to New Zealand; it is found naturally in North and Central America, particularly in California. According to the NZ Plant Conservation Network website (http://www.nzpcn.org.nz/flora_details.aspx?ID=3660) Miner’s Lettuce became naturalised in NZ in 1896, meaning it has been here a long time! A plant is naturalised when it is successfully reproducing on its own in a new place. This trailing plant likes to grow in shady areas and seems to occur mainly in the South Island. It grows to a maximum height of 40 cm. The leaves are 5-40 mm long, usually with a long leaf stalk (petiole). It has pink or white flowers in spring and summer and these are grouped together in clusters above pairs of leaves which are joined together around the stem and appear circular.
Miner’s Lettuce is actually a very useful plant. Its name comes from the fact that during the Californian Gold Rush (1848-1855) miners used to eat it to prevent scurvy as Miner’s Lettuce is high in vitamin C.
The Nature Watch NZ website (http://naturewatch.org.nz/taxa/36351-Claytonia-perfoliata) also mentions that this plant is eaten raw in salads or boiled like spinach. Of course, you should always be very careful when looking to pick wild foods to eat. You need to make sure you know what you are eating is safe!