Orchards of threatened plants
Bec Stanley - December 2015
If you want lots of apples, you plant an orchard. If you want lots of seeds of a threatened plant you do exactly the same – plant an orchard.
We have an orchard at the Gardens of the shore spurge (Euphorbia glauca) so that seeds can be harvested for restoration projects. Seed orchards are a really useful contribution Botanic Gardens can make to preventing the extinction of plants because the orchards can be established and the seed harvested when it’s needed.
Shore spurge (also known as waiuatua & waiokahukura) is one of Auckland’s rarest plants. It’s almost completely disappeared from Auckland over the past 100 years. It was at most beaches Auckland wide and now is found at only two, both on offshore islands: Hauturu (Little Barrier Island) and Motukorea (Brown’s Island). It has been eaten by stock, rabbits and snails, trampled on by beachgoers, built out by houses and roads and out-competed by weeds.
There’s a catch with our seed orchard of shore spurge and that has to do with harvesting the seeds. It’s not like picking apples! The plants in this genus have exploding seed heads – one minute they are hanging in the capsules in the plant and next – they’re gone, often quite a distance never to be seen again. While this is a great strategy in the wild to ensure the seeds find new places to grow away from their parent plant, when you want to collect them it makes it quite tricky! To try and catch the seeds we have picked the fruiting stalks (with ripe capsules and seeds on them) and placed them into a mesh bag and hang it up so that when the seeds pop out and collect at the bottom of the bag. Watch us collect seed.
If you want to learn more about this rare plant, click here.
