Conifer pollen

The Korean fir Abies koreana in our garden has been releasing vast amounts of pollen over the last few days. 

These are the male, pollen-producing cones near the ends of the branches. Like all conifers it's wind pollinated and the pollen released is quickly diluted in an enormous volume of air, so it tends to be produced in great quantities. If you give the tree a shake it briefly hangs like a yellow cloud in the air.

These are the pollen grains under the microscope, magnified about 80 times.

If you look closely you can see that each pollen grain has two inflated air sacs, which are extensions of the pollen coat. These increase the surface area of the pollen with minimal increase in weight, so enhance its aerial buoyancy.

Click here for more on conifer pollination.

This is where the pollen grains are heading - the new female cone at the top of the tree. Only a few of the pollen grains will successfully complete their journey and fertilise the female ovules, which are arranged in pairs on the upper surface of those whorls of cone scales.

At this time of year they are an attractive shade of purple but by autumn, as they seeds develop, they become brown and then break up through the autumn. Coal tits are particularly partial to the seeds - click here for photographs of them picking the cones apart.

Vandal identified

This year the Korean fir Abies koreana in our garden has produced its best cone crop ever. They usually stay on the tree well into winter but over the last week they've begun to disintegrate, with more being reduced every day to a spiky spindle. I thought it might be the dry autumn that was causing the cones' premature destruction but this morning I discovered the real cause..... 

.... and this is the culprit. I watched for half an hour while it made made repeated visits, pulling the cones apart.

This is what it was after - the seeds, which have purple papery wings. There are two seeds attached to each of those fan-shaped woody cone scales.

The bird is totally obsessed with plundering the food store that it has discovered - so much so that it allows us to approach quite closely to watch. At the current rate it will have trashed all the cones within about a week.

Korean fir is an ideal specimen conifer for a small garden, producing a reliable cone crop when just a few years old. Ours is growing in a very large pot and doubles up as a Christmas tree. The attractive cones are held upright on the branches and are purple when they first develop, ripening to brown and topped with very fragrant resin. And, as it turns out, excellent food for coal tits and if brings them into the garden, that's a plus.