As part of the Scottish Plants Project we are trying to understand the propagation requirements of 170 of Scotlands’s most threatened or vulnerable species. We are well on the way to achieving this, but some of the trickier characters have been left till last. Many plants have mycorrhizal associations with fungi in order to exploit their soil environment more effectively. However mycorrhiza are essential even for the germination of many orchid seeds. So to work out how to grow some of our threatened Scottish orchids, first of all we need to know which fungi they require to germinate.

There is an established technique for doing this which involves collecting seed, packeting it into very fine mesh within glassless slide mounts and then reburying these packets in the same site as the seed was collected. This is exactly what we set out to do over the last month, collecting seeds from two sites in the Cairngorms, then cleaning and packeting it and returning it back again.

Ripe seed heads of Pseudorchis albida, Small White Orchid

Packeting up orchid seeds

Andy Scobie, Cairngorms Rare Plants Officer, reburying seed packets.

We will return next Summer to excavate a proportion of the packets and see if the seeds have started to germinate. If they have, then further investigations can be made into which fungi are involved.