Cork news

On Saturday, I paid another visit to the cork oak on Clay Hill Green, noticed here from time to time, in particular at reference 1.

It did not look too bad at all, although the leaves were a little curled. Hopefully with the drought now ending, they will uncurl.

I thought to look to see if I could find any acorns. Maybe they had grown a bit since August? 

Without much success on that day, but zooming today turns up these two likely looking bulges.

However, before I got to that image, I had fed Google Images this one, with what I thought was a likely looking bulge in the axil of a leaf. In the first instance, he opted for an oak gall, a product of wasp action, rather than an acorn. What might be the dead flower at the apex right notwithstanding.

In response to a supplementary, he explains that while cork acorns are usually a one year thing (alegre) , ripening in the Autumn, sometimes, in response to stress, they switch to two years (tardio), more or less shutting down for the winter of the first year and only getting going again the following summer.

He allows that this might be the case here, but we agree that short of dissection - which is not going to happen and in any event I do not have a microscope or otherwise suitable magnifier - I am just going to have to wait until next summer.

I then poke around my snaps a bit harder and turn up the first one, and he agrees that they are dormant acorns, not galls.

I then think to take a look at the references Google Images provide, and that takes me to reference 2. Then there were references 3, 4 and 5. I shall report further in due course.

PS 1: I now know that the cork oak is an important crop in the western Mediterranean, that it is rather an unusual tree, and one which has been extensively studied. I don't think that the taxonomy of the sub-section, cirrus, which contains the cork oaks, is terribly settled. For the curious, there is plenty of this sort of thing to be found at reference 6 - all 860 lines of it.

Male and female flowers are usually separate, but are to be found on the same tree. The flowering arrangements can be complicated, with variations seemingly as much down to environment - perhaps drought - as pedigree. Not a good foundation for taxonomy.

But the bottom line is confirmation that there are two year acorns and that the bulges above are dormant female (♀) flowers, waiting to kick off next spring and turn into full-blown acorns. The oak galls were a red-herring.

The snap above is taken from reference 2. The middle 'b' labels the new shoot in year n+1. The left hand 'b' is an annual acorn, which may be contained within one year, or may spill over into the beginning of the year following.

The snap above is taken from reference 3. The bulge lower left looks quite like my bulges.

I also turned up a poster from a cork oak conference, but I decided that this was only helpful to the specialist.

PS 2: a bit later, looking at reference 7, the Australians seem to have pitched their taxes on nicotine a bit too high. When will we learn that trying to bear down on something that lots of people want to do, some of them quite badly, is going to make problems?

'... Australians spend A$8.5bn (US$6.1bn) a year on illegal cigarettes and vaping products, according to criminology professor James Martin — twice as much as the combined spend on cannabis, cocaine, ecstasy and heroin...'. Cartel heaven.

And it strikes me that Australia is very big country, with very open borders, albeit beaches. Can't watch all of them.

References

Reference 1: https://psmv6.blogspot.com/2026/08/the-first-short-circuit.html.

Reference 2: Biennial acorn maturation and its relationship with flowering phenology in Iberian populations of Quercus suber - Pedro M. Díaz-Fernández, José Climent, Luis Gil - 2004. My reference: file:///C:/Users/jimto/Downloads/QsuberPedroTrees2004.pdf.

Reference 3: Phenological phases of Quercus suber L. Flowering Maria Carolina Varela, Teresa Valdiviesso – 1996. My reference: file:///C:/Users/jimto/Downloads/Phenological_phases_of_Quercus_suber_flo.pdf.

Reference 4: https://en.wikipedia.org/wiki/Quercus_suber.

Reference 5: https://en.wikipedia.org/wiki/Oak_apple. Galls look as if they grow to be around the same size as acorns.

Reference 6: Updated Classification of Oaks: a Summary - Béatrice Chassé - 2018. To be found in the Journal of the International Oak Society, No.29.

Reference 7: Australia battles black market for cigarettes after decade of tax rises: How policy created a multibillion-dollar opportunity for organised crime - Nic Fildes, Financial Times - 2026.

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