Too hot for tinder – how orchid matchmaking is helping threatened flora in a post-fire landscape
Let’s face it – it’s pretty normal nowadays to use a little outside help in finding a suitable partner. While humans have countless apps, websites and even the old-fashioned face-to-face encounter, for our native plants and animals it isn’t that easy.
The buttercup doubletail (Diuris aequalis) is definitely an orchid to swipe right for. Aside from being spectacularly named, this endangered ‘donkey orchid’ has to be one of the most eye-catching native flowers out there, with its vibrant yellow hue and intricate design.
This orchid had a belter of a year last year, despite much of its habitat being burnt by the 2019-20 bushfires. When threatened species officers descended on Kanangra-Boyd for the annual monitoring, not sure what to expect after such a tumultuous start to the year, they were ecstatic to be graced with tons of beautiful, vibrant yellow flowers carpeting the ground! All up it was a record season, with just over 1000 orchids recorded and the area of the known population significantly expanded!
But, the job wasn’t done yet, as another critical task for the expedition was hand pollination and seed collection. Hand pollination is the process of manually pollinating a plant – so taking the pollen from one flower and placing it on another plant. Normally this job is reserved for animal pollinators, like wasps and flies, but sometimes humans have to step up to the plate and take on the job for a day or two.
There’s a few reasons to hand-pollinate a plant – in many cases we do it because many plants rely on specific pollinators to do the job for them, and there might not be enough of these pollinators around, particularly after a bushfire. However – in the case of the buttercup doubletail, we did it because we wanted to collect their seed.
Long-term seed storage at the Australian Botanic Garden Mount Annan is crucial for preserving the remaining genetic diversity of our threatened plants, and hand pollinating and seed bagging threatened orchids is a sure-fire way to guarantee we get those precious seeds. Having seed in storage protects the population from ever disappearing for good. Should some unforeseen event wipe the wild population out, we have our backup seeds in storage.
So how does one pollinate a tiny orchid you may ask? Orchids like the buttercup doubletail contain ‘pollinia’ rather than loose pollen. Pollinia are sacs of pollen encased in a waxy coating with a sticky disc designed to adhere to a visiting insect. Toothpicks are used to cross the pollinia from the flowers of different plants. These plants are then bagged with a fine mesh, and the ripe seeds will fall into this bag instead of dropping into the soil. Our threatened species experts then return several months later to collect these (hopefully) full seed bags.
In just one bag, there can be many thousands of dust-like buttercup doubletail seeds to be collected, all thanks to romantic interventions by dedicated SoS staff.