Bee Orchid Lifecycle

article written by Ellen Lee, TVERC Data Manager

Have you ever walked, cycled, or driven down a road one day and noticed some bee orchids growing on the verge, only to realise a few days later that they have been destroyed because the verge has been mowed? Well I have, and it nudged me into finding out more. Does mowing kill a bee orchid? Can it regenerate and grow again, perhaps in the following year?

Bee orchids are one of the more common orchids in the TVERC area as can be seen from the distribution map of records for the last 10 years. They like calcareous soils and disturbed ground which makes them an enthusiastic coloniser of road verges and brown fields sites. For most people living in towns, they and pyramidal orchids are the most like orchids they will encounter.

They are both beautiful and also iconic as a prime example of a plant evolving to entice insects to pollinate it through mimicry. They have evolved to induce male bees to try to mate with them and hence to pick up pollen which is handily packaged in a so- called pollinia. It has been shown too that bee orchids not only mimic bees in a visual sense, but also in a olfactory one by emitting chemicals called allomones that mimic the smell of a female bee. It’s odd then that the bee orchid has gone to all this trouble because UK bee orchids are almost 100% self-fertile and don’t actually need bees at all! Their self-fertilised seeds, which are small and light and blow on the wind, are perfectly viable. Like many orchids, the bee orchid has a symbiotic relationship with a fungus and the seeds will only germinate if it is present in the soil.

So, back to my original question. I asked local ecologist Judy Webb to explain the lifecycle of the bee orchid, and she did so by sending me this diagram, drawn by one of her pupils at Milham Ford School in Oxford when she taught biology there. As you can see, assuming conditions are right, it takes 4 to 5 years for a seed to grow into a flowering plant. The bad news is that if that plant is mown before setting seed, it will not be able to re-grow. It takes all its store of energy to flower once. If it is mown before it puts up its flower spike, there is some evidence that it can continue growing and flower successfully. Mowing verges later, well into July, with removal of the cuttings to reduce the nutrients available to plants that otherwise might outcompete it is the recommended management.

Having discovered all of this, I’m going to be trying and to find who it was mowed my local bee orchids and try and explain to them that inappropriate mowing is one of the biggest threats they face.