Native orchids
Keep your eyes open for our unique and beautiful native orchids
nYou’ve probably got native orchids in your lawn – they’re so small your eyes just need to adjust
ew Zealand native orchids have a reputation for being elusive but that’s because, the experts say, most of us don’t know what we’re looking at.
“They’re just about everywhere,” says Bill Liddy, who manages Iwitahi Heritage Protection area on the Napier-Taupo Road, New Zealand’s only reserve for native orchids. “You’ve probably got some in your lawn. The biggest problem, though, is that they’re so small your eyes need to adjust to see them.”
The national Orchid + Flower Show at Auckland’s ASB Showgrounds from September 22-25 will include a display about native orchids and registrants can join a native orchid ramble in the Auckland area led by Noel Townsley being held later this month.
“You can find just about all of the terrestrial ones right beside the track when you’re in the bush,” says Noel, a member of the NZ Orchid Council. “You don’t have to go off into the undergrowth. It seems that opening up a track lets in a little more light and the orchids like that. There’s a lot flower from May to August with a bit of a lull in September and then another burst from November through the summer. But I’m sure we’ll see flowers if we go to the right places.”
Botanists are still coming up with a final tally but there are about 130 (perhaps even as many as 150) species of orchid endemic to New Zealand with 95 per cent growing in the ground (terrestrial) – a reverse to the rest of the world where most orchids grow in trees (epiphytes).
“We’ve only got about eight epiphytes,” Noel says, “and nobody seems to know why we have so many ground dwellers. We even have one species – gastrodia – that doesn’t photosynthesise so doesn’t have any leaves. The plants live entirely underground, get their nutrients from specific soil fungi and once a year send up a flower spike.”
The most common native orchids that people are likely to know from bush walks are, in fact, the few epiphyte types. Anyone who has caught a nose full of Earina autumnalis (despite its name it flowers in summer) won’t forget it – the small white flowers, which grow several to a short stem, pack a fragrant punch.
Another bush beauty is the bamboo orchid, Earina mucronata, with its spray of long foliage and long stems of yellow flowers. Both these orchids are found throughout the North Island and much of the South Island.
Of our 130 or so native orchids only about a dozen are truly unique to New Zealand with most of the rest also being found in Australia.
“Orchid seed is like dust,” Noel says, “so the theory is that a good proportion drifted across the Tasman on the wind. Supporting this is the fact that the Australian orchid Pterostylis curta turns up in New Zealand from time to time and although it gets established, it dies out because it has no pollinator.”
Many of our native orchids that originated in Australia have got round the problem of not having natural pollinators by becoming self-fertile – meaning the flowers don’t need to be big and bright to attract a pollinator.
Others, such as spider orchids (corybas), have found their own way round the tricky pollination issue by mimicking a mushroom to attract fungus gnats to pollinate their flowers.
“Not having showy flowers has also probably kept our orchids safe from human predators,” says Noel, who has been an orchid enthusiast for the best part of 60 years. “People don’t recognise them as orchids so leave them alone.”
You won’t – or shouldn’t – find native orchids for sale in garden centres. Apart from the fact that many of our ground orchids are deemed by conservationists to be at risk or threatened, the plants live in a complex relationship with soil fungi and, in some cases, the trees they grow under. Remove them from where they’re growing and they will invariably die.
But not all native orchids that grow with a tree require their partner to be local. Amazingly, some prefer to set up home with exotic trees. Chiloglottis valida, for instance, is found in Hanmer Forest and Iwitahi, both exotic forests. Bill, who had a background in forestry before developing an interest in orchids, believes the orchid may have arrived in the 1940s and 1950s, carried as seed in the trouser cuffs of Australian foresters.
“The experts say there’s no pollinator here for them but the plants at Iwitahi are expanding faster than just by multiplication of tubers – and I’ve seen seed pods on them.”
Since 2008, Iwitahi, which came into being in 1987 after a Taupo Orchid Society field trip two years earlier had recorded an abundance of native orchids, has been administered by the NZ Orchid Council.
It boasts some 33 species thriving on a 14ha site among an old stand of Pinus nigra, part of the original Kaingaroa Forest. But the fact that so many native orchids enjoy growing with a single exotic tree has Bill scratching his head. “You occasionally find the odd one under a radiata pine but that’s all, so the nigra clearly has something going for it.”
He believes it’s a relationship between the high needle cast from the nigra pines, which builds into a thick mat, and the mycorrhizal fungi that develops underneath. “It seems to be a catalyst for the orchids being so profuse – in summer it’s wall-to-wall orchids here.”
But the relationship also has a downside. “Unfortunately, gastrodia prefer an environment with phytophthora fungus, which is killing the Pinus nigra that we want to keep. But without the phytophthora we wouldn’t have the gastrodia. It’s a catch-22.”
Volunteers are replanting Pinus nigra to replace ageing and fallen trees – as more light is let into the site, the number of orchids drops – presoaking seedling roots in an anti-fungal solution and spraying the trees with copper to improve the strike rate. Adding to the tenuous nature of the reserve only one nursery – in Nelson – grows Pinus nigra, which isn’t a commercially cropped tree. ✤