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Plant Focus

A small but mature Alabama sandstone oak producing acorns © Patrick Thompson
A Critically Endangered dwarf oak 

The Wivenhoe Park Millennium Oaks Collection

The following article by Maria Fremlin describes the oak collection in Wivenhoe Park at the University of Essex, Colchester, in the United Kingdom

In memoriam Professor Tim Gray, 1937 - 2018

Wivenhoe Park has a distinguished past. Richard Woods landscaped it in the late 18th century; he conserved old existing features and added extensive planting of English oaks and sweet chestnuts. Later, General Francis Slater Rebow, the owner at the time, commissioned the famous painting by John Constable: Wivenhoe Park, 1816, now in the National Gallery of Art, Washington DC, U.S.A. (Fig. 1). This painting features some mature trees around the lakes. Much later, in 1962, the County of Essex presented the University of Essex with the park and since then the University has maintained its landscaping traditions. These days Wivenhoe Park has some ancient English oaks (Quercus robur) and even a couple of magnificent cork oaks (Q. suber), which were brought by General Rebow from the Peninsular War as cuttings inside his boots – as one of the stories goes (acorns would have worked much better).

Wivenhoe Park by Constable
Figure 1 - Wivenhoe Park, Essex by John Constable
National Gallery of Art, Washington, D.C., U.S.A., Public Domain

Oaks are the most widely distributed of forest trees and very diverse; worldwide there are about 500-600 species adapted to all kinds of habitats. Therefore, they seemed the perfect choice to mark the millennium, not only to continue the park's traditional planting, but to reflect the international nature of the University as well. 

This ambitious project was the brainchild of Professor Tim Gray of the Department of Biological Sciences, who took charge of its meticulous planning. A few years before, a great variety of oaks were raised in various nurseries in Essex and Suffolk. Nearer the time, persons who at some stage were involved with the University were invited to plant a tree connected to their country of origin. 

Q. faginea
Figure 2 - Quercus faginea (center), planted by Maria Fremlin in the Wivenhoe Park Millennium Oak Collection

On the 29th of November 2000 many people turned up to plant 60 oaks, whose natural habitats ranged from North America to the Far East (Oak trees to mark the Millennium 2000); I planted an aptly chosen Portuguese oak (Q. faginea) (Fig. 2). I confess that this oak was unfamiliar to me because it does not grow in the north of Portugal, the area I was brought up in. Years later I had a lot of trouble locating it, let alone all the other even more exotic millennium oaks. Where were they? Soon I found myself involved with a fiendish puzzle. With the help of various people, plus many short field trips, it took me about four years to unravel it. In order to raise the profile of this collection, I present below the result of my amateurish investigations.

The Millennium Oaks Register

The planting of the millennium oaks is recorded in a book: Millennium Oaks Register (MOR). This book is in the Albert Sloman Library at the University of Essex and may be consulted only by appointment. In it every millennium oak is beautifully hand-illustrated on two pages of very thick paper: the left page describes the person/s who planted it and their dedication; the right page has the scientific and common name of the tree, a leaf, a brief description of the tree, its origin, and finally the Tree Plan number; see for instance "my" oak (Fig. 3). To accompany this book is another good resource: the Commemorative Tree Register map, which follows the same numbering system, approximately.

Figure 1
Figure 3 - Page in the MOR for the Portuguese oak number 19

The MOR is another mystery waiting to be solved, because its author, illustrator, and binder are not mentioned. Luckily, quite by chance, I found out that Richard Hull was the illustrator. Richard is a member of the Colchester Natural History Society and is a well-known wildlife illustrator

Field results

In order to locate and identify this collection, I relied on two resources: the MOR and the Commemorative Tree Register map. Given that to start with I had a less than basic knowledge about oaks, their identification was an incredible challenge. Oaks have great leaf variation, and introgression (the transfer of genetic information from one species to another as a result of hybridization between them and repeated backcrossing) is common among oaks, thus complicating matters even further.

To facilitate the location of the oaks in a park that covers 200 acres, in Table 1 I indicate their coordinates, OS grid 1 reference, who planted them, and most of their black tag numbers. These new barcoded tags are placed rather high and sometimes are either difficult to locate or missing. Only one oak has a dedication plaque, number 52; three oaks have a red label because they form part of Christopher Howard's University Tree Trail, which is available online: https://www.essex.ac.uk/about/wivenhoe-park. I have also created an interactive Google map, including a few photos for each tree, Fig. 4.

Figure 4 - Interactive Google map of the Wivenhoe Park millennium oaks

Throughout I have used the Commemorative Tree Register map numbering system. 

Understandably a lot has happened in the last 18 years, but on the whole the trees have done rather well. At the time of writing (September 2018), there are 52 millennium oaks in the park – an excellent survival rate.  

Some trees have grown far more depending on their location in the park. For example, the Algerian oak (Q. canariensis), number 40, near the South Courts is a magnificent tree, perhaps the largest tree in this collection; but the other one, number 17, in the north of the park is far smaller and doesn't look so healthy. Another splendid tree is a cultivar of the chestnut-leaved oak, Q. castaneifolia 'Green Spire', number 9, north of the park (Fig. 5). It is far bigger than the one that belongs to the Tree Trail, number 30.  

Q. castaneifolia
Figure 5 - In the center, Quercus castaneifolia 'Green Spire', number 9

Of the three Turner oaks (Q. ×turneri), the one near the North Towers is the far better specimen (number 6), closely followed by the one near the Wivenhoe House (number 21). The latter was planted by Professor Tim Gray and Paul Hance, Grounds Supervisor, to mark the origins of Wivenhoe Park (Fig. 6).

Q. turneri
Figure 6 - Quercus ×turneri, number 21, with the Wivenhoe House in the background.

Some trees I could not find; others have since died, are not doing well or have been removed. Furthermore, six of the extant oaks differ from the planting listed in the MOR. For example, "scarlet oak" number 8 is a red oak (Q. rubra). Conversely, oak number 34 is a scarlet oak (Q. coccinea) but was supposed to be a Hungarian oak (Q. frainetto). In theory, three Cambridge oaks (Q. ×warburgii) were planted, but there was only one in this collection, number 55. Sadly, this interesting oak did not do well; it was cut down and left as a stump obscured by lots of odd suckers; finally, the whole lot were removed. The second Cambridge oak, number 31, was a red oak instead; but it has been felled recently to allow for some relandscaping. I could not find the third one, number 42. The Caucasian oak (Q. macranthera), number 49, did not last very long; its replacement has also perished.

Q. rubra Aurea
Figure 7 - Quercus rubra Aurea Group, number 7, showing golden foliage in spring

In some cases, trees supposedly of the same species look oddly different. For example: there are two golden red oaks (Q. rubra Aurea Group), numbers 7 and 54, but only the first one goes golden in the spring (Fig. 7). Yet the other one is not a plain red oak. Some of the scarlet and pin oaks (Q. palustris) need rechecking. I found them extremely difficult to identify. One of the four sawtooth oaks (Q. acutissima) has very strange curled leaves, number 53. 

The main problem was with the identification of Portuguese oak number 60, which was planted by Professor Ivor Crewe, the Vice-Chancellor, and others (see photo in Oak trees to mark the Millennium 2000). Ironically, during the subsequent construction of the Ivor Crewe Lecture Theatre it had to be removed. However, the replacement oak looks rather different from the Portuguese oaks numbers 19 and 47; some experts have even noticed a certain parentage with Turner's oak. There are two subspecies of Q. faginea: subsp. faginea Lam., and subsp. broteroi 2 (Cout.) A. Camus. (Amaral Franco 1990); but as there are problems with their nomenclature and identification (Tschan and Denk 2012, Vila-Viçosa et al. 2014), I will leave the Portuguese oaks as Q. faginea sensu lato.

Summarizing, at the time of writing this collection comprises 25 species (Table 2). Their identification is by no means perfect or definite; I should like corrections from experts. During my fieldwork I have also noticed that some species have galls – interesting new records for non-native oaks. This is a fascinating project for cecidologists.

The Wivenhoe Park millennium oaks were an inspirational project that has undoubtedly enriched the park (Fig. 8). I hope that by writing this paper I might encourage more people to become involved with them. 

Q. xcrenata
Figure 8 - A few millennium oaks near the South Courts; front row from left to right, Quercus ×crenata ‘Ambrozyana’, number 51, Q. palustris, number 50, and Q. garryana, number 52, is the small tree partially visible.

Table 1 - Planting and location of the millennium oaks in Wivenhoe Park. Notes and abbreviations: x, not found; ≠, species different from the one in the MOR; ∆, the vernacular name in the MOR is Mexican oak; ◊, Commemorative Tree Register map number differs from the MOR number; d, diseased or dying; +, removed;  †, dead; », tree replanted at a later stage; ‡, very large specimen; TT, Tree Trail.

Table 1
Click on the image to access the table in PDF format


Table 2 - Extant oaks in Wivenhoe Park millennium collection. The scientific name, native region and leaf characteristics are mostly according to the MOR. Notes and abbreviations: ‡, this cultivar name is not known to be published; ≠, the new name for this hybrid is Q. ×crenata ‘Ambrozyana’; ∆, Mexican oak in the MOR; *, species not included in MOR; d, deciduous; e, evergreen; sd, semi-deciduous; se, semi-evergreen.

Table 2
Click on the image to access the table in PDF format



I'm extremely grateful to Christopher Howard for his support; without his help I would never have been able to solve this fiendish puzzle. I also appreciate the help of the following: Carlos Vila-Viçosa for a constructive discussion about the diversity of Portuguese oaks and their problematic identification; Roderick Cameron for critically reviewing the manuscript; Oisin Kelly for sharing information; Mark Ager, Rob Davey, and Marcus Clayton of the University of Essex Grounds Staff for general information and a copy of the 2006 Commemorative Tree Register map; Nigel Cochrane, the librarian, for access and feedback about the MOR; David Fremlin, my husband, for support during field trips and for converting the tree coordinates into the OS grid references; and Rowena Macauley for the idea of creating the Google map.


Amaral Franco, J. do. 1990. Quercus L. In: Castroviejo , S., Aedo, C., Laínz, M., Muñoz Garmendia, F., Nieto Feliner, G., Paiva, J. and Benedí, C. (eds) Flora Ibérica 2: 15-36. Real Jardín Botánico, CSIC, Madrid. http://www.floraiberica.es/floraiberica/texto/pdfs/02_041_03_Quercus.pdf

Tschan, G.F., Denk, T. 2012. Trichome types, foliar indumentum and epicuticular wax in the Mediterranean gall oaks, Quercus subsection Galliferae (Fagaceae): implications for taxonomy, ecology and evolution. Botanical Journal of the Linnean Society, 169, Issue 4: 611-644. https://doi.org/10.1111/j.1095-8339.2012.01233.x

Vila-Viçosa, C., Vasquez F., Meireles, C., Pinto-Gómes, C. 2014. Taxonomic peculiarities of marcescent oaks (Quercus, Fagaceae) in southern Portugal. Lazaroa 35:139-153.

Oak trees to mark the Millennium. Wyvern, December 2000, No. 3, University of Essex.


All photos © Maria Fremlin, unless specified.

1 Ordnance Survey National Grid: a system of geographic grid references used in Great Britain

2 Now considered a synonym of Quercus tlemcenensis Trab.