Acorn Time Approaches

Quercus miquihuanensis, grown from seed collected by Nick Macer in La Peña Nevada, Tamaulipas, Mexico. Arboretum de la Bergerette, Saint Sardos, France.

Abundant rain in southwest France in the early part of this year has fostered a bumper seed crop at Arboretum de la Bergerette, some (such as Quercus emoryi) already ripe: thus my thoughts turn once again to the seed exchange forum I mooted, which is at present under construction – many thanks to those of you who have already contacted me on the subject, confirming that the idea is worth pursuing. It will run something like this: an e-mail address unique to the seed exchange forum will allow members to send in requests or offers to donate, to be entered into a table accessible to IOS members, which I hope will also be able to give some idea of the likelihood of pure offspring, and with contact information to allow requests directly to the donor (you are reminded, of course, to check the restrictions in your country applying to importing or exporting seed). Also available on the website will be a forum where members can add and discuss seed-related information, which I hope will in addition provide feedback that can be input to the table.

Quercus hintoniorum from seed collected by Thierry Lamant in Sierra de Arteaga, Coahuila, Mexico

Along these lines, I received some interesting observations from a Polish enthusiast, Zbigniew Ptak, who visited the Arboretum last autumn and took acorns from several species. Out of eight acorns of Q. rysophylla which germinated, six sprouted at the same time, and appear to be “the real thing”, whereas two germinated five or six weeks later and appear to be hybrids: this led us to wonder if there might be a practical application of this difference in germination strategies (perhaps to identify “hidden hybrids” which are otherwise visually close to the species), and whether the same effect can be identified in other species.

The other thing which is under (re-)construction is my house, and the abundant rain mentioned above means that work due to have finished at the end of June has in some cases not even started (it is now, of course, the holiday season…): this completely torpedoed the possibility of holding the UK Oak Open Days in July at the Yorkshire Arboretum, for which I unreservedly apologize. The basic problem, of course, is that at present the OODs are overly dependent on my presence – thus a request: is there anyone out there, preferably resident in the UK, who would like to take on the job of facilitator on the day(s) of such an event or even, dare I ask, organize the whole thing? In the case of this year, our potential host, John Grimshaw, is next available at the end of September, but some of you may feel that this is rather too close to the California Conference; please feel free to write to us at tours@internationaloaksociety.org if you would still be interested in participating at short notice: perhaps something can still be salvaged from the wreckage if I can find a co-conspirator. If not, 2019 beckons.

Left: Quercus saltillensis acorns, on a tree grown from seed collected by Béatrice Chassé near San Antonio de las Mazanas, Coahuila, Mexico; center: a particularly handsomely striped Q. saltillensis acorn; right: self-sown seedlings under the Q. miquihuanensis tree, only one of which, (upper right of center), shows obvious signs of introgression, in this case, the toothed leaves (click on images to enlarge).

Quercus aff. galeanensis from seed collected by Thierry Lamant in Sierra de Arteaga, Coahuila, Mexico

A confession: having had a family reunion in November, we felt entitled to avoid Christmas altogether last year, and thus we went to Marrakesh, Morocco. An exhibition in the city was devoted to “shared sites of religion”, a feel-good title which enticed us within. One of the exhibits was a handful of acorns with Cerris-section cupules, entitled the “Abraham Oak”. No other information was offered other than an old photo of an even older oak, so my curiosity was piqued. The oak in question is an ancient Q. coccifera subsp. calliprinos (often referred to in older literature as Q. pseudococcifera, an invalid name) at Mamre, near Hebron in Palestine, and now a dead trunk supported by metalwork, albeit with a young sprout at the base (for which we should be thankful – a tradition holds that when the tree dies the Antichrist will appear…). The tree was once 18 meters tall with a trunk circumference of 7 meters, according to the Guide illustré des chȇnes, and old prints show the tree with a full head of hair in the late 19th century. However, construction work in the 1970s damaged the roots, and the tree withered a few years afterwards. The bible states that Abraham camped for some time amongst the Oaks of Hebron (although some translations replace “oak” with “terebinth”, Pistacia terebinthus). As long ago as 1868 the Russian Orthodox Church acquired the site, which in 1996 was subject to a territorial dispute between two branches of the Church. As well as being a site of Christian pilgrimage, it was in the past also much visited by Jews – since the Hebron accords with the Palestinian Authority their access has apparently been limited, so the site appears to be one of shared reverence rather than shared access. Since 2016 Russian experts have attempted to preserve the dead trunk (although the import of the necessary potions has at times been difficult) whilst at the same time avoiding damage to the young sprout. Images at various stages in its history are available on the internet (but beware “internet truths” on some sites pertaining to the tree, and in addition internet search confusion between the Abraham Oak and oaks at Abraham Lincoln’s tomb).

Finally, as of now I’m going to give up offering unsolicited advice to trees. The leggy Quercus saltillensis I castigated recently for making too much structure at the expense of leaves obviously knows better than me: planted in June 2012, it is now (a still leggy) 7 meters tall, and this year is having babies — bright green acorns which might yet find their way into the mooted seed exchange…

Left: Acorns from Abraham's Oak at the "Shared Sacred Sites" exhibition in Marrakesh's Dar el Bacha Confluences Museum - Right: Abraham's Oak

Photos © Shaun Haddock